Just saw T2 3D last night. Very enjoyable. I'd forgotten what a thoroughly entertaining film it is. Big audience genuinely laughed in all the right places, too. I think Cameron's made some digital tweaks (a la Aliens) for this version: I recall the driver in some of the bike stunts looking not terribly like Arnold, and that's changed. I also recall the composite shot of Arnold rolling toward the camera away from the crashing cryo truck looking pretty dodgy, but it's much more seamless now.
Anyway, highly recommended, and I can't wait to buy it on blu-ray. I hope Cameron gets to give Aliens the 3D treatment - that shot of Gateway Station would be glorious.