These guys just started selling yeast in February:
http://www.theyeastbay.com/
I've used a number of the strains/blends and the beers have turned out very good. They have been talked about a lot on HBT and Reddit where I usually post, and since I just joined BN I thought I'd share. There are a number of really unique offerings, and from posts on Facebook and the newsletter, a lot more to come in the near future.