I found two interesting interviews with David Simon on the web site for Baltimore magazine:

One is about Generation Kill and his next project, Treme. Money quote from the interview:

Interviewer: What’s next?

Simon: Treme. A story set in the musical culture of post-Katrina New Orleans. The title is that of a historic and predominantly black neighborhood just back of town from the French Quarter. We have a green light from HBO on the pilot but will have to wait until next summer to know if we are to film the first season.

Here's another one from back in February.