For softball, it would seem UCLA would certainly improve the league and would likely be a league favorite when they join (assuming they are at same level). One cool thing is now being able to host UCLA for series, which would be fun. There isn't going to be any short road trips for them in the conference. It also means B10 softball would have an odd number of teams (with USC not having softball); so brings a scheduling challenge.
I think similar story for baseball - they will improve baseball overall, but I'm wouldn't expect them to be dominant (thinking more along the lines of Nebraska when they joined, maybe slightly better).
Agree with rowdaboat on travel. Can you imagine USC/UCLA to Maryland/Rutgers trips? LOL
Might bring geographic divisions to these sports?