I can speak from experience when I say that Austin's entrepreneurial community is welcoming, supportive, and full of very sharp folks. You should definitely check out the Lean Startup group (http://www.meetup.com/Austin-Lean-Startup-Circle/). Our next meetup is a joint holiday mixer with a lot of other Austin groups (like Austin on Rails), and it promises to be a great way to meet a ton of folks.
Also, I'm not sure if you're looking for a workspace with a lot of people in the same position, but we've really benefited from participation in the Austin Technology Incubator.
How big is the Austin startup community? Austin seems like a hell of a lot nicer place to live than the Bay Area, but I'm afraid I'd miss the incredible magnitude of the support available to startups here.
Also, I'm not sure if you're looking for a workspace with a lot of people in the same position, but we've really benefited from participation in the Austin Technology Incubator.
Edit: why do I say folks so much?