I'm supposed to correct you and say that it's "iPhone 3G S" with a space, but it's a stupid name no matter how you type it. :2thumbs:
It still has a lot of things in its corner to handle multitasking better. I've been able to crash Safari by opening several large web pages, but that won't be a problem with 256mb RAM on board. Whatever push notifications is supposed to do is certainly going to help, and if all else fails, there's the app available through Installer than does allow real multitasking.
Believe me, I'm not trying to push the iPhone because there are still plenty of things to complain about that will keep me from using it (or recommending it), but Apple made the right choice with 256mb of RAM.