The WCC is a good landing place, as well as an upgrade, for UCSD - and UCI, if they're moving. It's a non-football conference, with basketball and soccer as the headline sports. The big difference is enrollment. The other WCC schools are small, religiously affiliated schools. In the long run, UCSD could become like the 800lb. gorilla in the chimpanzee exhibit.
I remember listening to the basketball game in which UCD won the D2 national championship. The enrollment differential was all the announcers talked about. Similar thing here.
I don't know if UCSD will be an 800 pound gorilla when there are still three schools in the top 100 in St. Mary's, USF, and Santa Clara. The WCC will be a nice conference with the addition of UCI and UCSB.