In the spirit of knowing that sometime in the next 100 years somebody may want to talk about this book, I will continue this thread. You can thank me later. 
For starters, I’m not an English major. I don’t really care about character development (I prefer it if the protagonist fails, but most books aren’t written that way) and if a story is missing the problems of a human heart against itself, I don’t necessarily find that to be a failing in the books and novels I prefer to read. So I don’t really care if the protagonist recovers from his Flashback addiction, or reconciles with his son, or whatever, I’m more interested in whether the damn story fits together, if the setting makes sense, and other boring technical details of the book.
David Brin wrote in the introduction to Earth that 50 year extrapolations are among the most difficult of exercises because they require you to modify the current world in a more technical way than a space opera set 600 or 6,000,000 years in the future, where you can handwave your societies development by saying “in 2212 AD the interstellar empire was born with the development of the hyperdrive…”. With a <50 year extrapolation, your starting point is now, which makes it all the more difficult to be believable.
Dan Simmons has done the space opera thing before in his Hyperion and Endymion series, so I know he can do large scale world-building, but in Flashback he attempts to extrapolate an America that will exist just 30 years from now - unless things go horribly awry, most of us now would live to see this America, so imho, it had better be believable.
(I’m going to go ahead and spoiler-box this - the book is only a month old, after all. And I’m on page 182, so if I’m completely wrong in what I say, assume, or believe to be true about this book, that’s Dan’s fault, not mine. )
[spoiler] I thought Brin’s Earth was unlikely. Possible, but very unlikely. However, compared to Flashback, Earth looks like the Oracle of Delphi… unless you are Der Trihs or Gonzomax, whereupon you probably prefer the future of Flashback. 
In 25 years, because of the Obama administration passing huge entitlement programs that the government couldn’t afford (the possibility of cancelling these things never crossed anybody’s mind in this world, btw) the economy has completely collapsed, with the US in what the characters mockingly refer to as its 23rd year of jobless recovery. There’s about a 50% unemployment rate which has gone on for decades, people are living in cubicles built within abandoned shopping malls, etc. The entire US economy exists to pay the interest on the debt caused by the entitlement programs we were too stupid to cancel.
But the US doesn’t exist anymore, I don’t think… it’s a bit confusing. Hawaii broke off. Alaska seceded. Mexico suffered a civil war, causing 22 million Mexicans to head north into the US, overwhelming the federal government (this migration called the reconquista). Texas broke off from the US and somehow, without the assistance of the US army, resisted the migrations (and safely removed it from Simmons’ story, freeing him the pesky need to write about Texas). The Japanese have bought all the US debt and are now in sovereign control of the US, dividing the remainder of the country into 7 economic zones. However, the characters keep referring to the “United States” as it is some viable entity, so like I said, I’m a bit confused on this matter. Hopefully clarity is forthcoming).
The only thing the US is good for anymore is providing soldiers and military gear to the Japanese and Caliphate armies. Nevermind the fact that military might is a function of economic might, America just rents out its army and navy to the Japanese. Because making war is all we’re good at or something.
The top global power is the Islamic Caliphate (China burst apart in a spectacular economic bubble collapse and are no longer a superpower), who vies with India and Japan for global dominance. The United States is now a predominately Moslem country, with 9-11 being remembered as a national holiday as the first strike against the American Hegemony (this holiday being enacted no later than 2030 (19 years from now)). The worlds largest mosque now resides at Ground Zero.
But you see everybody is cool with this because 87% of the population is addicted to Flashback, where they spend most of their days reliving our favorite memories in a full tactile hallucinagenic (sp, but I’m too lazy to look it up) trip - so if I wanted to relive my first sexual experience (or my first good sexual experience), I would take flashback and relive the act.
So I’m reading this and I’m thinking WTF? 30 years? In 16 years, I’m to believe that the now-predominately Christian US will be Islamicized (is that a word) enough so that we will accept a 9-11 holiday celebrating the terrorists POV? I’m to think that 87% of the country gets addicted to Flashback? (It is stated that the drug itself isn’t addicting, it’s the reliving the best moments of our lives that is so addicting. I have a good life but I can not believe that it’s been so good that I want to spend the rest of my life reliving it). Japan is going to invade China using an “endless stream” of US troops? Really? In 30 years?
Just because we owe them money?
And that’s the problem with this world (if I understand it right, which I may not: this entire spoiler-pity-party may be completely off base) – it’s predicated on the assumption that the US government and people would never default on its debt, that whoever owns it (the Japanese, in this book) would be able to literally claim swaths of the country as economic and human collateral, where the people of the United States exist largely to service the debt, even to the point where we institute mandatory military service so we can serve as the shock troops in Japanese and Indian wars.
Also, he posits that in 16 years, all of the current population will be Islamicized enough to accept a 9-11 holiday in support of the terrorists viewpoint.
And that we’re fine with this and were fine with it up to the point where the novel begins (no mention of a US civil war, except for the secession of TX, AK, HI, and the reconquista) because everybody is addicted to Flashback. He makes it a point to mention that all Americans are flashing back to happier days (pre 9/11 or pre-collapse), but none of the characters (so far) have bothered to do so, all reliving days since the collapse.
I mean… really?[/spoiler]
Dan Simmons tends to make big mistakes in his works – for example, in the Hyperion and Endymion books, he screwed up when
in the Fall of Hyperion Dan has a monster, the Shrike, remove a cross-shaped object that allowed resurrection from a character’s chest (Father Paul Dure), only to have this person resurrected in the next novel because of the object still embedded in his chest, the object removed in the previous book. There was also a rather large on in his Olympos series, but I can’t remember what it was.
In this one, it’s his timeframe. Had it been 75 years on out, with the US losing a war or three, I can buy it. But in 30 years and without a fight, the US collapses to the levels in Flashback? I don’t buy it.
And I won’t even go into Six Flags Over the Jews.
This book is weird – it’s a right-wing horror story complete with entitlement-program spending destroying the country, an overwhelming Islamic wave overtaking the world, and blaming Obama for policies that, in the real world, he hasn’t even enacted. And this from a guy who teaches English in what I thought was a pretty lefty town (by US standards), Boulder Colorado.
It would have been nice had he shown us he was this tighty-righty before.
Oh wait, he has.
Dan Simmons is my poster child for Artists Who Turned Right After 9/11. I know there are others, but Dan was a mild-mannered English teacher pre-9/11, now he’s warning us of the impending Islamic Caliphate. (He didn’t have much respect for it in Hyperion, but in that book, Islam was an afterthought - most of the population was irreligious).
The plot (a murder mystery) is moving along nicely, but there are a few too many blatantly expository characters - people who seem to exist merely to fill in some part of the background.
I recommend it, especially if you hate the US. Or Obama.
).