No one knows but Nikon. But since they updated the 200-400 3 years ago I highly doubt there will be an update anytime soon. Personally, I doubt it will be noticeably better than the nikon for most typical outputs.
Integrated TC? Interesting concept. Personally, I would rather NOT carry the extra weight all the time. Of course I am the kind of person who removed the tripod foot on my 70-200 to save that extra few ounces when having to lug camera gear around all day.
$12K is also very expensive for a 400 f4 lens.
In any case, we will see what happens when production lenses hit the field.
It's great that shooters using that other brand have a new tool...
I use my 200-400 Nikkor with and without a 1.4TC and do see a difference in IQ. It's not huge but I use the TC less than I otherwise might and I work to get a little closer to my subjects (which is better practice anyway). What I want to see tested is the IQ difference on the Canon with and without the TC. Reviews are saying since it is dedicated to that lens the design can be optimized over a generic TC.
The motorized drive on zooming sounds cool for video folks. The price hurts for anyone!
It's a very interesting piece of glass and one I'll be trying soon as a friend pre-ordered his a year ago. However, for 11 grand I won't be jumping ship to Canon.
The C 200-400/14TC is said to be scary sharp with the TC engaged and I wouldn't doubt it as Canon's TC's are generally regarded as being sharper than Nikon's. Still, you have to use a Canon body- a big downside as they are more prone to malfunction than Nikon's and not as ergonomic-IMHO
Most pro sports shooters wouldn't be using a 200-400 mm lens.
Of course, it depend on what form of sport you are shooting, but, in motorsport( which is what I used to shoot),a 300mm f2.8,500mm f4 , 600m f4, or even 800 mm f5.6 are the preferred choices.
The reason I say this, is that due to ever increasing " run-off " areas, a longer lens is required. I went through the exercise many years ago with long lenses, and finally ended up with 500mm f4, then 800mm f5.6, and a 300mm f2.8. Add in a TC14E to the 300 & 500mm lenses, and I was covered.
I did purchase the Nikon TC17E (its OK),and a TC20E, but, unfortunately, that particular version of the TC20E wasn't sharp. Apparently, the new model is, but, I'm not buying.