You haven't been watching Edwards campaign for the past year Epic. He's never really been an "attack" politician. That's one of the reasons I like him so much. He's generally more content to stress his own record and his own beliefs and how he feels he's going to be able to make this country better, rather than savage his opponents. Even his attacks on Bush are generally more like "I disagree with this and think its the wrong direction for our country. This is how I'm going to fix it. [long detailed spiel]"
That's why he didn't gain traction in the democratic election process until late in the season in Iowa, because people were attuned to the highly sharpened attacks from Dean and Gephardt.
Personal opinion now. If Edwards doesn't do well on Tuesday, he's going to bow out rather than risk embarassment in the south, i.e. his "back yard." However, even in losing the nomination, he's prepared himself well for 2008 (if the democrats lose this year) or 2012 (if the democrats win two terms). This election was difficult for Edwards because he wasn't known on the national stage. Looking at exit polling and other indicators, Edwards has consistently closed the gap on Kerry when he's had enough time to let the voters get to know him. Unfortunately in this compressed campaign schedule, time has been a luxury he has not had.
What is good for Edwards however is that people are now very aware of him, and quite frankly, everyone likes him as a candidate. Democrats, Republicans, Independents alike. He will be remembered for running a relentlessly upbeat and positive campaign, and that sticks with voters imo. I think he's set himself up well for 2008 or 2012. If he had come in with a "brand name" like Lieberman or Kerry, then he would be dominating the process.
People are voting for Kerry not because they like him or really believe in him. Only because they think he can win. It's a feeling of "He'll do I suppose, but I'm not jumping out of my seat in support of him." That's a damning indictment of Kerry imo. But with Edwards, you not only have people who believe in him personally, but believe in his policies and quite frankly, trust him, from all sides of the political spectrum.
Frankly I believe that Edwards is eventually going to be president, and 2003-2004 was his political coming out. Even if he is defeated in the nomination process, I think this is truly a "win win" situation for him.