Let the speculation begin (or increase). It is being reported on The Kindle Chronicles and Lilliputing that Amazon has sent out press invitations for a press conference. There is little more information than the date and location (Sept 6, 10:30 AM in Santa Monica, CA), but it is widely expected that there will be an announcement about new kindles.
The current speculation is that there will be at least a lighted e-ink kindle and probably either a larger or at least updated Kindle Fire.