They should have put Scott Walker's name in there as well. If he survives the recall and remains governor, that is one candidate who -besides putting much of the Midwest into play- can really set the Tea Party base on fire as a man that the Democrats and their labor union 'mafia' allies tried to get rid of in a high-profile vote, but failed.
Walker is a remote possibility, but only if Walker crushes his opponent in the recall election and Romney is down but not out in the polls. However, Romney may not want to wait that long. The sooner he has a running mate, the sooner he or she can go out and do fundraising. Romney's campaign style needs as much money as he can possibly raise.