The main thing keeping me from doing this isn't processing power, but battery life. If Apple's estimates are correct, the 11" Air has 50% worse battery life than the 13" MBP, and the 13" Air has 30% worse. Since the weight of the 13" MBP is already light enough for me, the slight additional decrease in weight for a big decrease in battery life actually reduces its portability for me.
It was mentioned, that the battery life for MBAs was measured using stricter tests. Maybe difference is not as bad as it looks?
With regard to your first paragraph, have you tried disabling "Safe Sleep"? I do this on all my MBPs because I find it makes sleep more flakey.
http://hints.macworld.com/article.php?story=2007030221032892...
Your thing about sleep surprises me, as that's my favourite feature of the Mac.
Whereas I can't truly trust my Win7 HP to come back from sleep OK, my MBP is always perfect. It eats a lot of power while sleeping, which I've never really figured out - but it comes back like a champ every single time.
But, most importantly, the new MacBook Airs _scream_ in terms of responsiveness. I was thoroughly unimpressed with the 2008 and 2009 MBAirs, but these new systems are similar in name (and manila envelope thinness) only - definitely an upgrade in user experience for the casual user of productivity apps. I hammered on every app they had, bounced from iTunes to iPhoto to Pages, popped open terminal, and just basically hammered on the laptop the way I would at work - it was just "twitchy fast" responsive. It may not have the processing power of a MBPro, but it "felt" more responsive to me. I left the store excited and ordered a 4GB 13" system online immediately.
We'll see how excited I am after a couple weeks of usage (My MBAir should arrive in a couple days) - but, I'm pretty confident this will be my primary system for the next four years.
No question - the new MBairs will be cannibalizing several product lines at Apple.