If they keep up the innovation, I think they have a chance. They are really making cameras people want, with great new technology. I bought a NEX5 for its size and image quality, and its great (save for the menu system).
I think the same of my NEX-6; only wish it had the A7's menu structure because the menu structure is amateuristic and not user friendly if you need to change advanced options while shooting.
Sony needs more good (and reasonably affordable) lenses too; I'm not too impressed with their lens line-up and I'm getting to the point that I think I'll sell on my 16-50 & 55-210 OSS because I'd rather use adapted FD lenses.
You see, this is where I think Sony is turning a liability into an asset. I also figured it would be hard to leave Canon because of lens investments. Sony seems to be encouraging third parties to make adapters to use any lens with their cameras, WITH AUTOFOCUS. Leica lenses seem to be what a lot of Sony users are using, but certainly Canon lenses would work well.
I love my 50D, but Canon definitely annoys me with their constant arbitrary cutting features and segmentation of their products. They seem to never want to deliver their best, but simply what the market will tolerate.
Canon and Nikon both better wake up before customers leave in droves. Sony's cameras are still rough around the edges, but the features they offer are very convincing, especially when portability isn't an issue. I personally cannot afford a A7s now, but when I can, I think Sony will be ready for prime time, and will have smoothed those remaining issues (maybe one or two years).
Btw, my previous statement is correct--Canon does have a low light king-the 1DC and it is $10,000, lol.