AP:

In a major boost for John McCain, Republican presidential rival Mitt Romney signaled Wednesday he's not ready to finance a costly campaign in the states holding primaries and caucuses next week.... Several officials said that on the heels of a defeat in Tuesday's Florida primary, Romney's campaign was not attempting to purchase television advertising time in any of the 21 states on the calendar for Feb. 5.

Sounds like that's that.

--Christopher Orr

Update: A Romney official now tells TPM that "the campaign will be purchasing ad time today, though the official declined to specify how much and where." Not sure this really alters the tenor of the tale...