BlogBack in September 2006 Google replaced the post Katrina imagery with much higher resolution pre-Katrina imagery. In the last few weeks some people have been trying to make a case out of this as some conspiracy on the part of Google. Responding to this criticism Google has expedited the inclusion of new high-res post-Katrina imagery and has them up on both GE and GM.
More details at the Official Google Blog.
As a side note, the latest GE updates from last week are in GM as of today too.