Man Utd recently made a profit of £39million, and there were reports that someone in the management (I can't remember who it was) saying that the cash would be available if Fergie wanted to go for someone. The problem for the January window is that almost all candidates will be cup-tied for this year so we won't be able to use them in the Champions League.
The name that seems to be a recurring theme is Defoe, but as long as West Ham keep trying to get £12m for him it is doubtful that we'll make a move. If we are paitent and wait to see if West Ham stay in division 1 next season, we could then move in and almost certainly get him for less than £6. But with him not being cup-tied, we may be tempted to buy him in January so we'll have someone to take the heat of Ruud in the CL and the EPL.