I really don't care about 3D either, although I can see Nintendo doing some cool stuff with it. But it strikes me as similar to motion control, in that it'll be cool/useful for some types of games, but annoying/useless for other types. In my mind, 3D alone is not reason enough to buy the system (just like I wouldn't buy a TV just because it supported 3D). It's a neat gimmick that could be cool if used correctly, but nothing more.
I think the PSP2 will follow the iPod Touch/iPhone model and have one version with a phone, and one without. I think UMD will be gone in favor of 100% digital distribution, since the PlayStation store is already well-established in the largest PSP markets (NA, Japan, and PAL territories). I also think that PSP2 will be backwards-compatible with the PSP, but of course only for the games currently downloadable from PSN. Sony always likes to lead the pack in bleeding-edge technology - often at the cost of profits - so I think this is completely reasonable. If they weren't going this route, they never would have bothered with the PSPgo (which I always viewed merely as an experimental testbed for the PSP2).
I would also guess that it would have a touch-screen, but also the traditional DualShock-style D-pad and face buttons, but this time with dual analog sticks. This is the best of both worlds, and won't shoehorn developers into making games that are PSP-only (i.e. they can port games from PS2, whatever). It would also allow PSP2 users to download and play PS2 games on the device, which I think they will introduce with the PSP2 (I always thought it was weird that they haven't put PS2 games up on PSN, but I think that's because they're waiting for the PSP2 to do it).
My guess is that the PSP2 will be $299 with the phone+2 year plan, and maybe $229 without. That sounds like a lot, but the iPhone is just as expensive and people buy plenty of those.