They'll be better.
They've improved on Defense, across the board, by getting a real center fielder (instead of sticking Shawn Green in there) and getting rid of Troy Glaus.
The loss of Glaus will impact the power numbers somewhat, but I'll bet Chad Tracy hits at least 35 this year - he's been hitting them with much more regularity since the middle of last year. Gonzo suposedly has something to do with that. But Tracy won't give up runs with errors the way Glaus did, either.
The offense should also benefit from the loss of Royce Clayton. He's a stellar defender (who get's replaced by a Gold-Glover, so you're losing nothing there) but he can't hit. That's solved. We should also have a Catcher who can swing the bat a little.
Pitching-wise, the bullpen should be better... but it could hardly have been worse if we put Winston_Wolf in as the closer.
The starting staff is what worries me. Batista, the major change, has always been inconsistant. He's throwing 8 innings of one hit ball in one game... Then giving up 8 runs in 3 2/3 the next. B-Webb is a legit ace, but I'm really worried about Russ Ortiz behind him. He didn't look good last year. That said, the D-backs can't move him with his contract, and I did think it was a good sign when they got him. Hopefully he'll bounce back.
The rest of the rotation should be acceptable. I'm not really worried about 1, 4&5... It's 2&3 that bother me.
We'll see how it goes... The rest of the west improved, too...