I would love to see stations with other formats besides Classical or NPR try the membership route. Classic Rock, AAA, 60s Oldies? Sign me up!
Lots of them. AAA is mainly a non-com format around the country. Oldies is becoming that way because national advertisers don't use music radio to reach the demo. They typically will buy ads on news/talk stations if they want to reach over 65. Public stations are finding AAA is a good secondary music format for them, after classical. If OSU could get another license, I'm sure you'd see them start some form of AAA.
There are threads on in other places about favorite LPFM stations. What we see are professional radio people who retire, start an LPFM, and do whatever they want musically. By law, those stations can't run commercials.