First off, I am thrilled to see Pentax moving ahead with its DSLR line. For those of us who have stuck with 'em, this is definitely good news. Also, the SR in body could potentially be a big plus vs. some of the other players; Pentax should capitalize on the fact that now "all" your lenses have SR (as far as I can tell, at least modern AF lenses).
I have two D bodies, which I love, but I must say, a 10mp body with SR would be great, because it would help with portrait enlargements. That said, my wish list is small:
1. Faster, better low-light AF (to me, this would be reason enough to buy -- the D is good, but not as good as I sometimes would like at wedding receptions).
2. Faster FPS/buffer.
I won't argue with other folks' suggestions -- many are good. Bring it on, Pentax! We're wating. Next: in-lens focus motors...
Pete