Well the movie was okay, better than Terminator 3 at the very least.
I'm starting to become convinced that Bale has been at his Batman role for too long, it's sort of channeling into his John Conner performance.
Aside from that, some cheesy special effects that really made me laugh, decent action scenes, Arnold shows up at one point (well, his likeness), and it was generally fun and well made.
It doesn't even half-way approach Terminator 2 or 1, and the post-apocalyptic wasteland is a bit generic, much less the skull strewn wastelands of T2 or the junkyards of T1, just typical greyness with blown up shit.
However, it was fun, and I'll give it that, it didn't make me fall asleep at the very least.
Just lower your expectations a bit and it will meet them, it's genuinely good enough to be a satisfactory sequel, but it's not on the level that fans will be raving about it.