If Stevie Wonder went suddenly, especially in an accident, it would be pretty big news.
The death has to be out of the blue. If Queen Elizabeth dies in her sleep, that would be big news. If Queen Elizabeth is assasinated that would be ENORMOUS news.
Given that one requirement:
Paul McCartney
Bill Clinton
Kim Jong Il (in a military coup)
Osama Bin Laden
The Olsen Twins. At the same time. In flagrante delicto.
I love Prince, but doubt his death would garner as much notice as MJ’s. He’s not really been tabloid fodder for years, has aged relatively gracefully, comports himself as a pretty intelligent and mature (if really quirky) man, and while he was pretty young when he started out in the industry, he didn’t grow up from childhood in the public eye. It’d be big news in the pop music world, and I could see MTV and BET doing tribute marathons similar to what they’ve done for MJ, but unless the death was really unusual, I think it would only be “big news” for a day or two in the mainstream media.
How about we go off a bunch of celebrities and see whose coverage is the most intrusive? Start with Tom Cruise, and if we make it all the way to Paul McCartney, we’ll spare him.
The forgot to add, with each other. 
Though actually, no, I doubt that would do it. It’d be a freak show, but a short-lived one, relatively speaking.
The only one that could come close would be Kathy Griffin.
I disagree. That would blow the doors off of anything that’s come down the news pike in a looooong time.
Especially if he was driving at the time.
Within the last week there was an NPR report that specifically said that Row vs. Wade was not a big news item when it was announced due to Johnson’s death.
I have no specific memory of either but as a small child I was aware of the former president dying and didn’t even know what abortion was.
He is the greatest. Good call.
Michael Jordan would get some coverage too.
Maybe some big, old-time classic star. Someone named Elizabeth Taylor. What about say, oh, Olivia de Havilland, being that she’s the last of the big four from Gone With the Wind. (Vivien Leigh, Clark Gable and Leslie Howard).
Or perhaps her sister, Joan Fontaine? Maybe Shirley Temple? Someone like that.
Or how about some hardcore, hard living rockstar. If Keith Richards finally croaks, it’ll be BIG news.
I don’t think anybody beats Michael Jackson.
I’ve come across people in villages India who didn’t know that the earth went round the sun, who knew who Michael Jackson was. I once showed my cousins in India a film magazine with photos of Hollywood actors - they had no idea who they were.
I think you’re extrapolating US popularity internationally - What do people mean by “global” here? US & Europe, Oceania - sure the most popular Americans are fairly well known in Europe too, possibly Middle East, Japan and SE Asia, but does anybody outside of those areas give a shit? Everybody knew about Michael Jackson - Africa, India, China etc.
Ali’s fame is overrated - a lot of people in the world don’t care for boxing.
Re Michael Jordan - nobody cares about Basketball in most of the world. He’s more famous for his shoes.
Paul McCartney’s probably more famous for his break up with Heather Mills rather than for his music with most people under 25.
NPR and I will have to disagree. It was huge news where I was, but I recall it being plastered all over the national networks.
We can now rule out Gale Storm and Fred Travelena. This has been a bad week for celebrities.
Not to mention Mick Jagger! But I think the ladies on your list would not cause too much excitement, not even Elizabeth Taylor. I can’t see the BBC asking people in Japan and Singapore how her death was affecting them, like they did for Michael Jackson.
The question can’t be reduced to “who is more loved/famous/important”, because those aren’t the only factors driving the hugitude of this. Those factors are just the jumping off point that he shares with a very tiny handful of other people to start with, the only two of whom come immediately to my mind are Oprah and Obama. (Us white folks just don’t inspire the passion I guess.) Obama doesn’t count because he’s the President so there’s THAT.
So he’s already in rarified atmosphere. Add in:
Age. No, 50 is not a kid, but it’s not an age you expect death either. Anyone you might thinkin of who is solidly past 60 and coming up on 70 and beyond is not going to be a big kick in the head. We all die, and that process picks up in those decades. At 50 it’s still considered a kick in the head. Not as much as 30, of course. But it makes a difference.
The mystery and shock of it. How? Why? WTF?
The timing: c’mon, it definitely spiced it all up for his death to follow Farrah’s by mere hours, and knock her right off the front page.   There was a whole bunch of 70’s icon, baby boomer, competitive death match stuff added in, particularly in light of Farrah’s public death process.  It just seemed…deliciously rude.  
His persona2: he was SO freaking strange and mysterious and bizarre and fascinating that his completely shocking unexplained death is going to be extra-super-duper fascinating, as will be the aftermath with his weird family.
Because of the former, the post-mortem scavenging of his privacy is and will continue to be like…Elvis and Marilyn and JFK rolled together and exponentially multiplied. Gee, now that he’s dead can we pick through his diary, photo album, medicine cabinet, underwear and figure out once and for all what the fuck was wrong with that guy? Can we see his face without the makeup?
And then we come back around to the beginning…all of the above is attached to a truly towering figure in pop culture and a genuine giant of popular music, no matter what else.
And finally, unlike anyone else that comes to MY mind, he has resonance and value and presence not only in nearly every society on earth, but in two or three generations! MJ and I were born 2 months apart; he’s so much a part of the world I grew up in…for 40 years! And everyone younger than us. That’s a long time and a lot of people.
I really don’t think that anyone else’s death could overshadow his, frankly.
Elvis, when he finally dies for real [as SmashTheState already said]
>>Obligatory Abe Vigoda reference.<<
The Queen. She will die of natural causes but she has had a life that no one, not even vaguely resembles anyone else’s.
We will all be flooded with every detail the day she dies…even you Americans. Di proved that.
That will be THE furneral AND the day to remember.