I too have seen a big change in battery life since the 2.0 update. Previous to this, my iPod was at 1.1.4, no January update, and not jailbroken. I used to mostly use video and music playback with some web browsing.
But, the reality is that with 2.0 and the new apps, this is almost a totally different device. As with a new device, there is a very different usage pattern. I assume that many of the apps need more CPU to do their graphic magic, and it makes a lot more sense now to use wi-fi almost all the time - like with the app store, a number of the games, email, web, etc.... That is also very different from my previous pattern where I would use wi-fi and turn it off when watching videos. I am also starting to turn the screen brightness down futher than ever. I still do not really trust their auto screen brightness feature. I hope over time that apps might be more tuned for performance, but not sure I would count on it.
So, although I would love the touch too last much longer, I totally understand why it is not. it is my use of it that has changed, so I can not blame Apple per say. The value I am getting is way more than I ever asumd when I bought it.
I might actually consider looking at the Mophie Juice Pack for the touch. I think it is a pre-order thing now. I might try to just wait to September to see if a new touch is being planned. If not, I'll probably look at the Mophie.
Sam