"Greatness" doesn't lie in being an attack dog.  Edwards did today what most democrats are incapable of doing: he talked about reform ideas, about the future, he showed that the democrats just aren't the anti-bush, they actually stand for ideals and ideas.  Sure, using the few minutes he got on MTP to bash bush would've fired up the base, however, I would say that the majority of Americans are more interested in hearing about the possibilities for tomorrow.  And, Edwards gets that.  Bush is almost done, his approval rating is so low that the democrats don't even have to push on this guy's lows, what they need to do is convince a disillusioned country that THEY now have the vision to put this country back on track. People now know that Bush is a loser, now they want to know if the democrats are any better or not?  

Great leaders are those who talk to all their constituents... and Edwards always does: he talks to all Americans about what we can accomplish together.  He criticizes Bush a lot too at the events that he attends for democrats, however, I think it isn't caution, it is thoughtfulness, that forces him to rise above mere partisanship.  Of course, that wouldn't satisfy partisans like yourself, but anyone without an ideological agenda, should and would have listened to him today and realized that this guy is someone who is more interested in solutions, rather than talking points.  

Lincoln taught us that "a house divided against itself cannot stand" and he too was derided for being a "nice guy" in his time.  Well, there is a certain graciousness that accompanies great leadership.