If were an Apple share holder I would be ecstatic with today's news.
As an iPhone user I'm decidedly wary about how iAds will be allowed to be used by developers. That's a "time will tell" type scenario but one thing that Apple has proven in the past is that they don't much care if you like the way they think you should like things... Furthermore my 3G does limited multitasking just fine, I can talk and surf, listen and surf, download and surf and a whole host of other things. I'm sure the new multitasking is more complex but it's not like it doesn't already happen on the 3G (and even older) phones. Slacker running the background would be nice, that's all I'm saying. My motivation to upgrade will be when my map can turn from blue to red and they slap the A4 processor in the 4G phone.