I would do that trade. I think it would improve your team especially if the LeShoure from last week sticks around. I would be concerned about your WR depth though for bye weeks but that shouldn't have too big of an impact since you have real solid WRs. Moore and LaFell should be servicable replacements during those weeks but I would want to find someone a little more concrete. Hopefully Mendenhall comes back in a big way and you can flip him or LeShoure for another WR.