My nomination:
http://www.screensound.gov.au/images/gallery/White%20Stripes_web.jpg
They are mega.
Howdy 
I will admit that having the ability to stay ahead of the trend is a talent: Madonna’s made a career out of it. But, I don’t think that it alone can make an artist iconic. For every Madonna and Eric Clapton, there are countless others that managed a successful repositioning or two and then faded into nothing. Mariah Carey went from warbling Diva to R&B superstar with substantial success before later crashing and burning. Sugar Ray went from nu-metal to breezy pop before morphing into some embarrasing club/hip hop collision, yet are still seen as little more than your average MTV fare. Jewel’s gone from pop-folkie to teen-sex symbol, and if the number of times I’m seeing her video on MTV is any indication, she’s doing quite well out of it.
Pink’s managed to successfully rebrand herself once, a feat that, while increasing her longevity, is not in itself uncommon or even particularly interesting. If Pink can do it again and make another couple of successful albums, she may Madonna, but given the quality of her current work, I see no reason to suspect that she is headed for icon status any more than her contemporaries.
Not that I’m touting her as a future icon, but I think from the current pop stable, someone like Beyonce Knowles has a better chance at icon status than Pink. She’s already had success with Destiny’s Child, has duetted with some very successful artists, and her solo album seems to be doing good business. If the next Destiny’s Child thing works out, she could be headed straight to Madonna-ville.
Well, yeah, you’re right there. Perhaps my view on what constitutes an icon differs a little from others in this thread. Certainly those I mentioned will never draw the crowd that the Eagles would. I suppose my opinions should be read with this in mind, and likewise, my reading of others should take this into account.
I’m still convinced that Pink will never be seen as an icon, though, whatever definition you use.
So, WordMan, I’ve heard that you knew Patt Smith’s literary agent…
I agree, very cool ;).
Oddly enough, being unknown in the United States doesn’t necessarily make a band “unknown internationally”. Blur is a band that has enjoyed enormous success in a number of countries; by definition, they have achieved “international” success, despite a lack of American recognition.
I’d group DMB with your American country and western mega-stars: performers who have achieved enormous domestic success but lack the international appeal required to attain “icon” status.
I mean, we’re talking U2, the Rolling Stones and Madonna here. 
I still maintain, incidentally, that the lack of obvious icons emerging from the 90s is due more to the enormous range of quality recordings produced in that period than the supposed evil of record companies.
gex gex - nice discussion about artists staying ahead of trends and when that knack translates to “icon” status. I agree, and agree with your assertion for Pink - she hasn’t done it enough yet to qualify as an icon. YMMV, and I can see why you think she never would qualify, but she does have a strong, interesting voice and is not just interested in warbling - she seems to care more for the songs, so for that reason, I wish her luck.
And my use of “icon” vs. “legend” was spontaneous for this thread - we can use whatever words we want, but I am hearing that you agree with my basic take, which is that some artists are big sellers initially, critically respected (or at least not dismissed) and have longevity; other artists are either critically acclaimed at first or down the line - their influence is understood over time, but even then they wouldn’t necessarily fill big venues. Some of your examples - like the Velvet Underground or even Bob Dylan - have they ever had an album go platinum? I remember reading that Dylan’s son’s band, the Wallflowers, sold more of their album “Bringing Down the Horse” than Bob sold in his career (may not be correct, but I wouldn’t be surprised if it was close to true). My point being that Dylan is one of the most important, influencial artists of the rock era, but he lacks the mass appeal that is included in this thread with the term “icon” - so I chose to use the word “legend” for him and others…
Clapton hasn’t been hip in a pretty long time. What you say about him always watching trends is true, but I think a lot of fans these days think that’s all he knows how to do. He’s a legend because of his work from the mid-60s to late 70s, nothing afterward I’d say… the Crossroads boxed set and the Unplugged performance brought him back to the popular consciousness somewhat and probably gained him a new generation of fans, but his fame still rests on his older stuff.
Marley23 I basically agree with you - if you look at the quote of mine you used, I say “was always staying ahead of trends” and by that I mean the same time period you referred to, the mid-60’s to early 70’s…
Yeah, seems we basically agree on this. And the icon v legend terms work for me.
True - I’d never though about this. Dylan always seems so huge and influential that I’d never really thought about how niche he was in his time. Like you, I don’t know exact sales, but I wouldn’t be surprised if, as you say, The Wallflowers outsold him.