Halter has done good things in role as Lt. Governor, though the job is admittedly limited.
One problem that Halter may face is that he is not popular with the Democratic Party establishment in Arkansas. I think this is more personal than policy-related; there is some perception that Halter is arrogant. This may pose a bigger problem than in other places because Democrats hold all statewide offices and both chambers of the state legislature. This would be the first time in a long time that a Democratic incumbent statewide faced a primary challenge in a long time.
I have been an Obama guy from the start, but Biden was my 2nd choice. Joe added a lot to the dialogue, and I'm glad he ran. He did a great job of addressing the issues and forcing the other candidates to up their game in this vein.