Upload & Sell: Off
Canon's finally announced the 200-400+1.4; but has not said when you can actually buy one. B&H will allow you to pre-order one for a mere $11,799, and they also published this preview.
Renowned UK wildlife photographer Andy Rouse published a full review of the lens - he's been testing it for 6 months. Going by the article & the images he published on his blog, this looks to be the lens to get. Now who's got a spare £12k.