I just got a NX2.0 CD from Cameta for $119 and found that I could not open my D90 RAW file.
Called Nikon support and they had me go to their site and the download NX2.1 . You need to have the NX2.0 CD loaded on your computer before you upgrade. I have a very fast computer (Duo Core 3G Vista 64 bit with 8 G Ram) and the download (Cable) and compile took about 7 minutes.As it is an update to 2.0 no cost is involved nor do you have to enter the product code again.
At this time all of the NX2 CDS are v2.0.
While Vista 64 is not offically suppported by NX2,NX2 runs fine on my machine.
This is my first photo editior--the little I have seen so far looks great. I am sure I will be back with many questions.