I also want to add that the Redskins have pretty good depth at receiver, but without a #1 like Vincent Jackson or Marques Colston, everyone played a position above what they should be. Santana Moss isn't a #1 receiver anymore, Gaffney is serviceable like you said and Anthony Armstrong should be going out of the slot. It would be a pretty good group if they added one of those guys at the top.
The Skins have a bunch of number 2 and slot receivers. They have no number 1. Moss is the slot receiver. Armstrong is looking more like a bust. Gaffney should be replaced by Hankerson by Week 8.
There really is a lack of talent at the receiver position on the Redskins.
BTW, as to my opinion on this trade, I stand by what I've said since Week 4: Anyone but Rex Grossman