I remember reading  recently that Canon holds about 51% market in the DSLR category followed by Nikon, who also hold a major share, followed by other brands like sony, olympus etc.

I believe that Canon has done really well with the variety of lenses it has produced in the recent past but what makes it really special is the fact that it concentrates a lot of energy also into customer support. Probably, this fact is what gives Canon the edge over Nikon or any other competitor for that matter. 

Canon has also played an mportant role in curbing the gray market sales of its products. I happened do do a lot of research before buying my first dslr. I noticed that canon has in some way optimised its prices (although I still feel that they are astronomical), so as to reduce gray market sales.

I think Canon is making the right moves and we can clearly see that with the number of initiatives that it takes. The blogs, the canon edge program, photography contests and so on. This is a way forward and Im sure Canon is going to hold a majority of  the market even in the years to come.