Pat Scaramuzza, Calibration Analyst with SAIC at the USGS National Center in SD tells Boing Boing:
Satellite pictures of the NOLA area are just coming out. We've put our Landsat 7 pics on our image gallery (Link).
NASA has MODIS images up (Link).
None of these are full resolution, but they might help anyone who is trying to make a flood map of the affected area.