Rumors abound that Feinstein may retire in 2006 at age 73.
Frist is not running for re-election, he has a self-imposed term limit of 2.
CA Republicans cannot seem to find anyone to run for much of anything, as the state is so gerrymandered, but that wouldn't matter for a statewide race. Notice the "R" counties in CA are much, much larger geographically than the "D" blue counties.