PMA is right around the corner.
All of the camera announcements leading up should be a pretty clear indication of what to expect.
However, there are some other cameras expected to be announced and/or shown during PMA.
Canon is alleged to have a 1DsMKIII hidden up its sleeve, as well as a 5D successor and possibly a 30D successor.
All, with the exception of the rumored 40D are expected to feature a full frame sensor.
Now, Nikon is also expected to announce a new DSLR or two at PMA.
One of which is said to feature an almost full frame sensor of 1.1x (20.67mm x 31mm).
Here's a visual aid of what the 1.1x sensor's physical characteristics looks like when compared to Nikon's typical 1.5x APS-C and Canon's full frame:

Sounds good. We'll see though. 18-20MP I hear, and possibly a HSC mode so that you can still use your DX lenses. That would be cool. One thing that Nikon has done well is having very good compatibility between old and new lenses and bodies.