IF that's the case, then I'd agree. Having a replacement level 25th man won't kill the team, especially if his bat is decent enough for some pinch hitting duties (which it has been this year). If he's giving us veteran presents on top of that, well maybe he is worth keeping around.
That said, there is no way to quantify what effect he has on the clubhouse. Gibbons, AA, etc. are in better positions to make the call but even then I don't think they can really put a value on what those veteran presents mean to the team. Also, and this is the cruz of the problem IMO, it looks like another replacement level infielder is going to be on the team next year in Maicer Izturis who also plays the same positions in 2B and 3B. How many replacement level 2B/3B types do we really need? I say we let him go to the claiming team and use his spot on a more talented player, even if it means we won't be receiving as many veteran presents next year.