If you're planning to spend a lot of time at the park,
Disneyland, it may be good to stay right in Anaheim. In RCI, take a look at:
WorldMark Anaheim #A872 - due to open in Fall 2009
Dolphin's Cove Resort #4907 or WorldMark Dolphin's Cove #7602 (same resort)
I don't know if any of these are on
DVC's short exchange list or not. The new WorldMark is awarded and it would probably be worth requesting that they add it, if it's not. Who knows if DVC would consider it competition for the new DVC out there?
Anyway, if you're planning to do more spread out sightseeing, then there are several other resorts between Anaheim and San Diego. Do a search on RCI's online resort directory with the keyword Disney and filter for California. Consider joining
TUG - Timeshare Users Group for access to extensive resort reviews by timesharers, whenever you want to exchange and make a good selection. HTH.