I'd say this is pretty dependent on your league type, standings, and rotation. I don't see Utley or Rizzo as upgrades at this point (I'd rather have Morse than Rizzo for ROS), so the deal is really Votto for Moore. Moore has been a beast, so if you really need a starter for the ROS, I can see this being a decent deal. Votto probably won't return until September, and even then.. Unless it gets tight in the Central, they'll probably ease him back into the lineup so he's full gear come October.
If this is a keeper, ignore the above: keeping Votto is a no brainer.
OF (x3): CarGo, M. Bourn, D. Jennings
UTIL (x2): E. Encarnacion, C. Hart
BN: Cuddyer, C. Ross, J. Montero
SP: Price, Gallardo, T. Hudson, Lester
RP: Chapman, Jansen, Rodney, Putz, Cishek, Bailey