This isn't exactly a banner year for the Pac-10 basketball wise. Even the best team isn't considered a legitimate threat to win a National Championship. There is always the opportunity for a surprise, but the Pac-10 might not make much of an impact on the tournament this year.
According to the latest Bracketology update on SB Nation, only three teams from the Pac-10 are currently slated to make the NCAA Tournament. Arizona leads the pack with a six seed, and earns a very difficult first round matchup against 11th seeded Michigan St. Washington makes it as an eight seed and has a matchup against Old Dominion. And UCLA rounds out the group with a nine seed, currently slated to play UNLV in the first round.
But as I said, things could change. One of the other teams in the conference could win the tournament, earning an automatic bid. And there are a few teams that are currently pretty close to making the tournament as an at-large team in Washington St. and USC, according to SB Nation's Bubble Watch. A strong tournament run from either of those teams could earn them a trip to the tournament as well.
It should all play out in the tournament, but if things go as expected, only three teams will make the tournament from the Pac-10. And that doesn't really constitute a successful season.