I was so going to post the E! Online interview about Rob and his hair but you beat me to the punch.
Now for Edward the hair needs to stay but for Rob, I think he needs to cut it. It doesn't seem to me (that's only by the pics that I've seen) that's he's so into the grooming aspect of the hair.
Some guys can pull off the "bed" head but personally Rob doesn't do it too well, in my opinion.
*I will now go hide in the corner and try to keep the from getting hit by miscellaneous objects being thrown my way*