There's a story in the L.A. Times indicating that the Dodgers may keep Fox Sports in the fold they depart for Time Warner Cable, having Fox produce a small number of telecasts (I'm guessing around 20, but no more than 25) for Channel 11 or 13. This is, of course, to make sure the Boys in Blue still maintain a local over-the-air prescene.
As to Prime Ticket/Fox Sports West, let's not forget you still have the Angels around, and you have a case where the Halos could put some games on Prime Ticket to at least keep that channel somewhat viable. When the Yankees started YES Network in 2002, MSG Network also had the TV rights to the Mets games, and they split the broadcasts three ways--50 on MSG (to make-up for losing the Yanks), 50 on then-Fox Sports New York, and 50 on WPIX. Now, I don't ever see the Angels doing that kind of set-up like the Mets, largely because of the huge TV contract from Fox Sports, and in the final years that the Angels were on KCOP, they cut the OTA package from 50 to 25.
Six regional sports networks in the L.A. market is overkill, especially since the Dodgers insist that they have their own network. There is one thing that we should be on the lookout for, and it's the Clippers in a couple of years. Fox is in a somewhat venerable position in that the Clippers have a lot of leverage (big factor being that they're finally a consistently-popular and competitive team), where they could command a larger rights fee from Fox or the Dodgers could make an offer that they couldn't refuse.