Adam PNA, these are some valid and interesting points, I admit.
But :
→ Precisely 
As some iPhone games quality is really steppin up to big console quality, in term of gameplay, graphics and stuff, this is why players are starting to reach some big console requests.
I know it’s not the most relevant forum in the world, but this thread, or the parent of this site are two of growing signs that could lead to believe in growing expectations within the mobile player database.
This is not taken for granted, for sure, but these kind of signs are fastly reproducing all over the net.
Adding all over that the incredible attraction those success stories do over non gamers.
Oh and by the way, those big publishers like EA, Taito, Capcom, … When they will settle for real in the appstore, I don’t believe they would stick with 5$ games, at least for marketing balance. I’m sure they will be the firsts to dare throwing 20$ games.
Everything is lifting the stuff up, litterally.
I remember last January, when I started to dev my game, everybody around me was just “oh, we’ll see, good luck”, but now there are at least 6 people who are aiming at buying one, or even developping their game. Plus the friends who kindly brought me some collaboration proposals, whatever their domain was (music, networking, IA, etc).
There’s a big hype, for sure. With a hype, everything is possible.
But we’ll see, 'cause no one knows, I agree 
edit : sorry for the yadda yadda, I love speculations 