I'm a lot warmer to this idea than my head says I should be. I do think, as the Bull Moose charges, that nature and presidential campaigns abhor a vaccuum and Gore could be the one to fill it. Iraq will still be the dominant issue in 08 and a candidate seen as experienced and with an alternative view could attract a lot of attention. I also suspect that there remains a good deal of positive sentiment for Gore among Democratic voters who think he got shafted in 00.
That being said, what I said about the Iowa caucuses in the previous post would apply here. Gore would need to immerse himself in the state and present a broader range of issues and a softer touch than he has displayed previously. While a definitive, articulate stance on the war would be admirable, a candidate seen as too angry or bitter could turn off voters. I suspect caucus goers will tolerate bomb-throwing candidates (like Dean and Gore recently) up to a point, but the lesson from Iowa seems to be that voters also seek someone steady and unflappable. Gore would need to convince Iowans that he would be a stable influence in the White House and be able to ride above the partisan fray at least to a certain degree as President.