My iPad was charged overnight, took it off charge at 9am. It is now 3:30pm and the charge is down to 92%.

Today I have:

- used the app store to download and install 12 updates
- used Instapaper for 20 minutes to read some stuff
- done 5 minutes of web browsing
- watched 45 minutes of wifi streamed video using Air Player

After doing the first four items and before watching the video the battery was still at 100%.

That is a fairly typical performance for my iPad's battery life.

Edit:

This is a 3G iPad by the way, so it was also connected to a middling-flaky 3G signal at the same time as doing the above.