Some people at DPreview.com says they can't buy this lens anymore. As a Nikon user, I'm personally waiting for a Canon 5D Mark II competition (I'm really trying to force myself not to buy that camera specially that I was the Canon user before and switched to Nikon some time ago). Anyway, I own 70-200, 2.8 and it's amazing lens, but I think Canon's 70-200 is just little better and sharper.
Does the DPreview.com conversation means that there is an upgrade coming? Maybe. I wish it's going to be 24-400, 1.4 for the price of 70-200, hahahaha !

Source:
DPreview
Nikon Rumors