The iPad 2 is already screaming fast, and I don't mean that facetiously. It's a massive boost over the iPad 1, which already felt speedy and smooth.
I have yet to use either of the iPad 2 cameras
Retina display is something I'm not fully sold on yet. I've got both an iPhone 4 and iPad 2, and the resolution looks the same to me during normal use--probably because of different viewing distances. But if it's amazing and makes reading easier, sure, great!
I've used the iPad 2 camera during a business trip last year to New York to talk to my kids on FaceTime while they sat in front of my wife's iMac and read them bed time stories. At the time I had the iPhone 3GS with no FaceTime, so the iPad 2 was my only FaceTime-compatible mobile device. Now that I have the iPhone 4S (which camera I use all the time) I cannot see using the iPad 2 camera for much of anything. Especially now that I can snap a photo with my iPhone 4S and have it show up on the iPad 2 via photo stream in a matter of seconds.
How would they add thunderbolt? The iPad is too thin. If only it was thicker than MAYBE
Hmmmm..... I think if you saw Thunderbolt on the iPad 3 it would simply be yet another usage of the 30-pin connector. A cable that plugged into the 30-pinand had a Thunderbolt plug at the other end. Don't know if they have enough unused pins left for that (with charging, USB sync, HDMI, Composite Video, Component Video, and the SD-card adapter all consuming various combinations of pins). But it sure would be cool if it were possible. Incidentally, the old FireWire cables for iPod don't actually work on the current 30-pin connectors from what I have heard.