Personally I don't think it will die anytime soon. Heck, If we're gonna talk about dying, look at Opera. And even though Opera never got that much attention (they do make very nice browsers for Symbian mobiles, from my experience), it's still alive and developing.
@hanorotu: I'm currently using chrome and I notice that lag in it too. I've switched to chrome because firefox seemed a bit unstable handling flash applications (plugin container crashed often), and although chrome handles it a little better, I can still experience some problems. I've reached to the conclusion that the problem may not be with the browser, but with flash itself.