Indeed, the Pac-10 would probably become similar to the Big 12 and the SEC--a few more cupcakes to fill the schedule. The conference championship game would make up for that lost round robin game. However, anything special about the Pac-10 would be lost, replaced with a more homogenous product of twelve teams, two divisions that fits the distinctions of other big power conferences.
Finally, Cali49a does point out that this might makes the BCS situation even more intractable, as we'll now have more conferences on equal footing.
"I prefer to keep the Pac10 the way it is, but the conference is going to be jockeying for a new tv contract ($$$$$$) soon and having a 12 team conference with 2 divisions like the Big 12 is more appealing to the networks. The Pac10 needs to get with the times or it’s going to fall further behind the other BCS schools.
Personally, I don’t want the expansion to happen and wish the Rose Bowl would get out of its contract with the BCS. I don’t think that’s going to happen. Once again, the BCS and how it’s tied into the MNC is the biggest root of the problem."
What almost every reasonable college football fan wants is something other than the BCS. A Pac-12 might very well pull us away from that objective, with another extra game making it difficult for anyone to advocate playing any more games. Oh wells.