Oh, I hope not.
I like .epub and the fact that you can get it from so many different places and put it on so many different devices. It was my second criterion in choosing an ereader 6 months ago, and the reason why I ended up not getting a Kindle.
As for the general use vs. dedicated use, I'm with the ones that are for having several different devices do their job well, rather than one that does it all but worse.
I have an iPod for my music and audiobooks, my Reader for my books, my (mom's) camera for pictures and my Blackberry for phone calls. Even though my smart phone is capable of taking pictures and playing music and I can read books on it, all of those things it does worse then their designated devices, and I dislike it. So I walk around with several gadgets in my bag, even though many people have said "Why carry all that when you have a phone that can do it all?"