Edit: long rant shortened.
DS's success wasn't just luck. Stuff analysts could have seen right from the start:
DS and PSP had roughly equal third party support, which anyone checking the release lists could see.
Nintendo had the momentum of years of handheld dominance behind it.
Sony's price was too high - practically every competitor Gameboy has ever had was more more powerful and more expensive.
Sony was so caught up in marketing the PSP as a lifestyle choice that it forgot to mention it plays games. Oops!
How will Revolution do? I think it's impossible to predict that without seeing the games. If Nintendo proves it's got some truly great uses in mind for the controller at E3, and/or if it has significant third party support, then I think the analysts will be wrong. If it has a DS-like launch, then they may be right, but I really doubt it will have a DS-like launch. Nintendo saw an opportunity to beat Sony to market with the DS and took it. With the Rev, I think Nintendo will take it's time to ensure a proper launch lineup.
It's also a bit early to tell if PS3 or Xbox 360 will win, but assuming equal pricing on both systems, I think they'll be about even in sales, and PS3 will probably come out on top.