I think that this is for the best. If the other major products all absorb WinFS features, it will make a relational file system (when it comes) more useful. Rather than being a stand alone product with it's own API's and schema's, it will be a rather painless
upgrade, because all of the plumbing will already be there for the various platforms to use the data.
Edit: Sorry BryanF, I went to the bathroom while writing my post and didn't notice that I said mostly the same stuff I was in the process of typing.