I actually have a 1st gen iPhone (purchased after the first price drop ... Oct '07), so I'm not planning to upgrade until they have a 32GB version available.

The iPhone has a proximity sensor near the ear speaker that knows when your face is near ... that's how the screen shuts off.

Push email I haven't ever had here in the USA except on my Blackberry (for work), so I'll love it when it comes, but aren't missing it.

Battery life isn't as bad on the 1st gen iPhones. But, I still have to charge it every day.

My biggest gripe is how buggy the 2.0 firmware is. So many crashes, so many glitches, so slow. 1.1.4 was the sweet spot for Apple.