I also have am a moderator/owner of a Yahoo group and have been thinking the same thing. I probably will be turning it over to someone else to run tho since I am not as active as I used to be.
I set a list up on DH just to see how it works. Not bad. Not as many options as with Yahoo but no ads, no spamming, and etc.
I think the best part is that you have much better control over who sees the members lists. I am suspicious of how Yahoo harvests names.
Where are we going and why are we in this basket?
mine - http://holyroller.org
dog's - http://joella.holyroller.org