Everyone (meaning O-Dub, Eskay and the LA Times) is talking about how hip-hop is missing from the major Grammy categories for the first time in six years. But if you look at the psychology of the Grammy voter it's easy to understand how this happened.
The people at NARAS can't just elevate any old rapper. They're only comfortable with honoring hip-hop they can rationalize as being "special." Something with a twist that makes it more "artistic" and innovative, more substantial and respectable than all that other stuff.
Usually this means they sift through the bestselling rap albums, and find the one that had the most singing and the least rapping on it (see Lauryn, Andre 3000). If they have to grant "special" status to rappers who actually rapped, they need some other angle that makes the artist Uniquely Relevant, and then the rapping rappers usually get many nominations but few awards (see Kanye, Eminem).
But for whatever reason, 2006 was simply a slow year for "special" hip-hop. With Game, Jay, Nas and Snoop all dropping after the deadline, TI is the only rapper with enough sales to be in the running. And for the Grammy voter there is simply no way to rationalize TI as more than just some guy rapping over a beat. Does this mean it's time to panic about hip-hop losing its pop cred? Not hardly. It just means we didn't throw in enough guitar strumming this year, and forgot to tell interviewers how we've been listening to the Beatles.
(And just to prove my point, there were two hip-hoppers that played this role perfectly in 2006.. in fact they played it so well everybody must have forgotten they were hip-hoppers, since nobody has acknowledged that some cats named Ceelo and Dangermouse are up for Record and Album of the Year. This does puzzle me a bit, since I'm not sure what makes "Crazy" any less hip-hop than "Hey Ya." Maybe it goes to show that our perception of genre boundaries is as much about an artist's marketing and branding as it is the sound of their music?)