Well, that Pac 10 isn't as good as it has been historically, and it certainly isn't a good conference by any objective measure, but there's no way the conference only gets one bid come March. The favorite right now in the conference looks to be Cal, sitting at 10-5, has no great wins out of conference but explainable losses (to Ohio St., Syracuse, then undefeated New Mexico, Kansas, and UCLA in OT). Cal has had injury problems too, with Theo Robertson previously out and point guard Jose Gutierez currently injured. Bascially, it's a team that has a chance to gel and perhaps make a run at respectability in the tournament. Cal's RPI sits at 32, well within tournament respectability.
Washington also has the potential to be respectable and make it in. Washington started out strong at 10-2, but has lost 3 games in Pac 10 play. Washington has a good core who plays fast, and just needs to right the ship. Pondexter and Isaiah Thomas could easily get things together and put a run together at seasons end.
USC has been playing well, including beating recent- number 1 topping Tennesee , but will be unable to enter the tournament due to self imposed sanctions by the University for recruiting violations realted to OJ Mayo. While that may deflate the number of teams that can make the tournament in the Pac 10, it means the conference isn't as bad as the voters think.
However, all that being said, the rest of the conference is pretty damn lackluster. The nonconference schedule was brutual for the Pac 10. The conference's best win outside of USC's beatdown of Tennessee is Washington's victory over Texas A&M, ranked 35 in the current RPI. That's not pretty compared to years past. While the Pac 10 undoubtably looks way worse than usual, I'll guarantee that at least 2 teams end up in the dance, with at least 1 in the sweet 16.