I do not know what will be the camera market in 10 years. But I know that the EOS system is the more stronger today because in 1987 Canon had the courage to completely change your line of lenses and cameras. At that time, users cried and mourned the inconpatibilidade of new with existing equipment, but it allowed current lenses and cameras achieve the performance we know now. Nikon has good cameras and lenses, but risks with niche projects such as D800E, and the "new" Nikon DF. On the other hand, Sony has taken bold attitude with A7R why has not the most important in the long run: A solid line of lenses. If I had to choose which company to invest my money, would be Canon. The market of domestic cameras can change dramatically in 10 years, but professionals and serious enthusiasts will keep buying cameras and lenses that do a good job together.
I'm not certain I can agree that the EOS system is stronger because of Canon's decision to orphan all their previous owners. Since they felt the need to start with a (mostly) clean slate, they could have chosen the flange distance such that a high quality adapter for the FD mount lenses would have been reasonable (and profitable). They took a calculated risk that they wouldn't drive all their customers to Nikon (and remember they did hedge their bet by make a very special adapter for those few customers who had invested in the really expensive telephoto lenses), and it paid off.
They tested the waters (unsuccessfully) with their autofocus FD lenses, analyzed the market trajectory, made some strategic decisions, and were eventually proven to have chosen correctly.
But we'll never know what might have been if they had made the decision to make their new design adaptable to their old lenses. Perhaps they might have been even stronger. (although then Ed Mika wouldn't be in business)
But given their demonstrated lack of loyalty to the installed base, one has to wonder what 10 years will bring.