Yeah, I wouldn't be surprised if they don't make the WCF, but would I be surprised if they do? No.
I would say that it is hard to predict how far the Spurs will get, and leave it at that. Last year, they finished the regular season strong(I think 1st in the West), only to get eliminated in the first round against the Grizzlies.
This year, they've added more depth(STEPHEN JACKSON!!!), and Pop's been focused on the post season from very early on in the regular season.
I do like their chances against OKC. They have the talent, but they are still green. Dallas will be tough for sure. Lakers, if guys like Kobe, Artest & the two centers get hot, they'd be impossible to beat, unless we get Manu, Jackson & Duncan from 5, 6 years ago, but would those Laker players get hot? 50/50 chance at the very best IMO.