The PAC-10 released a "tentative" (but most likely final) version of their 2010 football schedule, with two games moved to Thursday and two more moved to the Friday after Thanksgiving. These changes along with others were done for television purposes.
Thursday 9/2 USC at Hawai'i ESPN (part of WAC contract)
Saturday 9/11 Stanford at UCLA ESPN/ESPN2
Saturday 9/25 UCLA at Texas ABC 8pm (part of Big 12 contract)
Thursday 10/21 UCLA at Oregon ESPN 9pm
Friday 11/26 Arizona at Oregon TBA (available to all TV partners)
Friday 11/26 UCLA at Arizona St. TBA (available to all TV partners)
Thursday 12/2 Arizona St. at Arizona ESPN 8pm
Also, all five rivalry games will be played on the final week of the season. Consequently, only one game will be played on 11/20: California at Washington St. and it could be a week where all national TV partners pass on televising the PAC-10. Oregon St. is also waiting to announce its 12th game, though preliminary reports listed Eastern Washington as the opponent.
For the UCLA-Texas game, that game was moved from 9/18 to 9/25 when Texas at Texas Tech was moved to 9/18. Florida Atlantic's trip to Austin was then moved from 9/25 to 11/20.
EDIT: Two games will be played on 11/20 as USC-Oregon St. was also moved to that date.