This is all speculation, not the lens, but the future plans of the companies. It makes me ask the question that if Nikon was on the verge of releasing a full frame D-SLR why would they go through the trouble of making this DX "digital optimized lens" a big story? The DX name seems to indicate a "line."
Obviously there are a bunch of D100's out there along with the Fujis. To eliminate the Fujis and depend on just the D100's, D1x, D1h, etc. seems short-sighted if you were on the verge of breaking it open with full frame D-SLRs. Since there are still a bunch of people on the fence with moving to D-SLRs it would seem that if they were to announce the availability of a earthshattering full frame 14 MP camera that can even drain pasta without removing the lid, it would result in further constipation of the migration to D-SLRs.
I personally don't think they've perfected it, and they are going to expand the opportunities for D100, professional D1 series and the Fujis. Sell Sell Sell. Get a good installed base with a bunch of glass and then do the Mega-MP, then people with the glass would obviously upgrade rather than jump ship to another manufacturer. The upgrade path may have slowed for a bit due to some unforseen problems (see Kodak) and maybe Cannon's suffering from the same thing and Nikon is biding it's time.
Then again, I may have just escaped from a mental institution, and something totally different will happen. (Ssshhh don't tell anybody!
) We may know in a couple of weeks at PMA, then again, there's also a chance that someone just may find an actual important difference between the D100 and the S2 to help people make an easy choice between them. 
Anyways, this looks like a great lens with flexibility for WA.