Does playing both systems make sense? Canon have no higher resolution sensor, and the Nikkor ultrawide is a renowned lens. Now Canon might be considering a higher MP body at some point, but it is still total vaporware.
For me it is working. I now have both a D800 and the D800E and I do prefer the D800E. I'm mostly a seascape and landscape photographer and you are right about the Nikon 14-24. It is a really great lens.
Now for the bad news. Perhaps I have a bad copy but I'm preparing to send my 24 tilt-shift lens for modification and repair (Nikon does not allow for tilting and shifting in the same axis unless you send it back for repair). The repair part is that I have an area on the left side of the frame (about 10-15) that is not as sharp as the right side and it never gets focused. I really miss my 17 and 24 Canon TSE lenses because of their ability to rotate tilt and shift into the same axis. Just great lenses but with the 14-24 and the 36 MP of the Nikon D800E just trumps it. And yes I have done the landscape test with both cameras on a bar shooting at the same time. The extra detail on the Nikon is a kick!
I'm keeping my Canon gear for now but I'm not using it very often. I'm waiting for Canon to pay attention once again to still landscape photography. I'm taking delivery on my 24mp D7100 crop camera for birding rather than waiting for the firmware to hopefully help my poor 7D 18mp crop camera. Where is Canon? They promised firmware for this camera last fall. It is now spring and they can't even get firmware to us.
For me the bottom line is this. You have to shoot with whatever best tech is available at the time. I have decided to go with both realizing that I will never be able to predict which camp will have the best products at the time that I need them. I can only tell you that using Nikon for the first time has opened my eyes to some better ways (like CLS lighting) that I was not even aware of before. What a treat!
Why am I also on this forum? This is Canon Rumors. I want to hear some Good Rumors of NEW Canon cameras. Nikon Rumors is too full of actual new Nikon Cameras and lenses being announced and then delivered. Even the manuals were available for the D7100 the day after the D7100 started shipping as well as the Camera Raw version for the new camera. What a treat!
I hope that Canon Rumors will once again be talking about announcements for a large MP Canon camera, actual delivery dates (maybe a month or two later), and new lenses that are affordable (like under 10k for a supertele like the 500mm mk2).