The West will come down to the same thing it did last year: playoff matchups, specifically who matches up well against who. The teams are too close in ability and too good overall for there to be one clear favorite. This year the Lakers got an ideal bracket of the no-defense Nuggets, no-answer for Kobe Jazz, and the Spurs with a hobbled Ginobili. If they had gotten the Mavs, Rockets, and Hornets, or a full-strength Spurs team at any point, they would have been much less likely to get out of the West. It's all going to depend on where the seedings shake out.
This is somewhat but less true for us. If we play the Wizards, Magic, and Cavs we might struggle; if we get the Nets, Sixers, and Pistons, we'll probably do very well. The East is weaker overall so it's less of an issue.