I'm on a 14 inch iBook with 1.25 GHz G4 (remember though, G4s are far superior to most other chips architecture wise, so you can consider that chip closer to a 2.5 GHz, same for your 1 GHz chip) and the same video card, though a lot less RAM (256, I need an expansion)
So far, it handles most of my current games pretty well, though I don't have WoW. Do realize that WoW will probably be optimized more for the final release, and have lower system reqs. You should be able to handle it fine, but do remember laptops have slower system bus and hard drives than their desktop counterparts.