Gawker seems overly focused on The Roots angle of this, but they do call Jimmy Fallon for what he is:
I've never had a group that I actually like go the late night house band route. Springsteen fans saw Max Weinberg take his act to Conan's show; and I'm sure there were some jazz heads who were flabbergasted to see their main man Kevin Eubanks signing up with Jay Leno. But The Roots? The Illadelph generals opening up for that stuttering mop-headed ball of suck, Jimmy Fallon?
More here.