I think Dean did very well making a recovery/comeback in NH by spending a lot of time doing town hall meetings (covered by CSPAN) and interviews with local in-state media. He should look to maximize that in some of the upcoming states, as they did with a series of interviews on Wednesday. Not to mention all the morning show appearances on ABC, NBC, CBS, CNN, etc. Lots of people watch the morning shows and a 3 minute interview there could do a lot more good than a couple days worth of expensive ads that everyone just mutes on TV anyway. This is free media and Dean is certainly still sought after for these interviews. Especially smart now that the media seems to be feeling remorse for all the Dean bashing.
Dean may not be running an ad blitz going into Tuesday, but that doesn't mean he'll be invisible to the voters.