I have both the iPad and iPad2. Both 32GB and 3G. For having the iPad2 about six months now, here are my thoughts:
1. WEIGHT -- iP1 is obviously heavier, however, I do feel safe throwing it around. Unlike iP2, which always requires my delicate touch. Probably iP1 is bulkier and doesn't have a camera at the back
2. BATTERY -- Both are upgraded to iOS4.3x, but iP2 needs charging every 2 days while iP1 still can survive for at least 3-4 days. I use iP2 in daytime in my office together with Macs, iP1 at home mainly for browsing and movies and tv. I suppose iP1 really have good battery capacity
3. WEB & DOC -- I see different things on the same site with both of them. Eg.. this site streamingtvforipad dot com, I use it almost every night lately for tv shows. in iP1, I can see the screenshot in the video before I play, but not in iP2. In my office, when opening the same Excel using the iPad Numbers, in iP1 the grid view is always organized, but iP2 always seems to have a problem with Excel converted viewing
4. CAMERA -- iP1 doesn't have a camera, so this is not comparable. However, the iP2 I'm holding is actually my third iP2 due to a faulty rear camera. Apple exchanged twice for me. I don't use the camera now except for app development when comes to augmented reality. The quality of the photos are grainy. It looks good when you took it and view in the iPad, but absolutely disgusting in iPhotos. I now use my Blackberry more often to take photos when needed.
5. SYNCING -- though I use the iP2 for work, both my iPads have all the same apps installed, and are synced daily. When there is an update for some apps installed, they will be updating the apps automatically in the iPads when you connect them to the iTunes. iP2 always takes 5 to 10 minutes longer to complete. This I'm frustrated because I thought a newer generation hardware is supposedly more advanced, in this case, speed. But it isn't.
6. 3G Reception -- both are using Vodafone supplied by my company. But for way too many times, iP2 seems to have better signal strength then iP1 while in the same location. This is more obvious either in Underground or a remote golf course.
To sum it up, I'm not so hype about iP2 but since both are company issued, I obviously took the better one back home for personal pleasure. iPad3 will definitely outbeat iP2 by far to get me consider buying it for myself. But I can say this, the screen size of iPad is really perfect for both work and pleasure. So they get headaches minus one.