I believe fatbikes are the future of mountain biking. I can see it splitting off into more categories, like calling fatbiking "All-terrain bicycling" and a typical mountain bike will be called XC or trail bikes since they are more or less confined to the trails.

But yea, I rode a Mukluk 3 and I had a revelation, which I promptly cleaned up, then went in to the store and put it on layaway. Picking it up next Thursday!