S P ... agreed. Ultra-wide is gaining popularity. Some of the hottest new lenses are UW. And UW is very useful in video.
however, unless you have deep pockets, switching brands is tooooo expensive on lenses. Bodies will come and go every couple of years, and each brand will have a turn on top. I expect Canon will step up with the FF lineup.
Well as someone who switched from Nikon to Canon (this past June), I can speak from first hand experience that it doesn't need to be super expensive to switch systems. For me it was a big investment as far as time and effort more than anything else, getting photos of all of your gear, listing it for sale, and then keeping track of dozens of messages and transactions. I actually pocketed a grand or two on the switch though.
It was a combination of Canon having a much better selection of lenses and not forcing me to more lens than I need like Nikon was, and buying and selling at wise times. Some stuff I even made a profit on.
If you're a full-time pro and are competing with other photogs for quality and results, it could be that you couldn't afford NOT to switch. In the grand scheme of things, a $10-15k investment in gear for a full-time pro is chump change, and a business write-off in the US as well. No big deal.
Yes, things do swing back and forth, so it'll be interesting to see what Canon comes out with next. I hope it's not 'yet more megapixels'. I personally prefer Nikon's quality over quantity approach.