Looking at the sensor size/IQ ratio on cell phones today, I'd be surprised if those don't progress enough to obviate almost any need for *any* mirrorless camera. That's the cannibalizing I see, especially given the huge value add of the phone's OS. This is particularly true of any tablet, b/c you get a giant LCD, too.
Instead of selling and supporting SLR accessories that facilitate ftp, wifi, wwan, GPS/geotagging, etc...to the camera, go the opposite direction-move the sensor to the tablet where that functionality AND MUCH MORE *already exists*-basically for free.
Imagine the sensor size you can get on a tablet compared to a FF camera. The current SLR form factor's limitation would be irrelevant. Just add a tripod mount on the side, you could be looking at ridiculous IQ for portraits and landscapes. Not to mention how much easier manual focusing would be at that size. Combine that with the ability to chimp on a tablet instead of a little LCD, then edit and upload immediately...
It gets better. You now also have a device to instantly share the pics you just took. No more nephews and clients gathering around and squinting at a little LCD. Either look at the tablet or plug in an HDMI cable and show it on your HDTV.
I realize the lens quality would be an issue, but how hard really would it be for somebody to make an EF adapter if he could get $2k for it?
If I am Canon or Nikon, this future is terrifying. You're looking at a one way ticket to niche-ville, purveyors of old school (again I am talking 5 yrs out) cameras that only sports/wedding photogs use for the FPS and AF speed.
Of course, I could be completely, wrong, too:)