Haven't seen any discussion of this anywhere, so it's apparently not a great idea -- however, it seems like the right move when you bring Rizzo up. Put Rizzo at first, Move LaHair to left, leave Compana and DeJesus where they are -- at least until Jackson replaces Compana.
Soriano's offensive numbers look much better at second base than at left. I find it very unlikely that we can move him in the next two years, if not all three on his contract, so we've got this issue like a sore in our mouth for quite a while going forward. Barney is no long term anwser at second anyway -- with weak OBP and Slugging. His D might be better than Soris, especially now, but that doesn't make him good. Nor does it justify not making the move.
Perhaps Soriano doesn't want to play there, I don't know. But, do we really care if he gets upset? Get Sveum or Theo to talk him into it.