I have sold my K20d and was planning on buying either the K-5 or a D7000, but was also contemplating a Nikon FF move. Of course, if there was a Pentax FF body, it would have been a no brainer. With the D800 news that just came out in the past few days (possible release Feb. or Mar. of 2011) it seems I will wait for that. Nikon rumors reports today that the French publisher of the book about the Nikon D800 will be released in March of 2011, so the camera would have to be out around that time.
K-5 - way too expensive and I do not wish to wait for price to drop
D7000 - was only going to be a temp thing until I went FF
D700 - not worth it now that D800 is on the horizon which will have video and 24MP
D800 - my most likely option now, however I am DSLR-less until it's out
I may opt to buy a D7000, or D3100 if they are not backordered in the next month, and then just sell it when the D800 comes out. This way I can pick up some FF Nikon glass and be ready for the D800.