I don't think so. Amazon is winning and has been winning because they've focused on a few key times-- The largest collection of books and price. They also focus on making their kindle an excellent reading experience.
As for the Apps, they have helped a lot, I'm sure a lot of sales are not made from the Kindle ownsers. However B&N where the first. After having acquired FictionWise they had access to all of the platforms eReader was ported to and they did not waste any time branding their name on all the different platforms.
I also strongly believe that is why Amazon started making Kindle apps for all of the devices. With B&N having access to millions of users, vs Amazon K1 & K 2 base B&N was in a much better position to win the book war.
The last point, and kind of implied already, is Amazon is very agile, and adjust to the market very quickly.