MCab was definitely a liability at third, but I honestly don't know if Guillen's legs will hold up for a season at 3B... that was the reason behind his move to 1B in the first place.
Let's see... Inge no longer at 3B, and Sheff still on the shelf. Does this give us any insight into whether Granderson will be playing CF tomorrow? I can't imagine that Leyland would DH anyone besides Guillen or MCab at this point, unless he was taking Magglio out of RF and putting Thomas/Rayburn/Inge there.
Hmm... I guess we'll just have to wait and see. In any case, I don't think changing things up a bit is going to be a bad thing. If anything it will give the defense a nice boost, and the lineup will remain mostly unchanged.