Daily Kos in conjunction with Research 2000 has released a new AR-Sen poll. The long and short of it is that Bill Halter leads Blanche Lincoln 47-44, with 9% still undecided (MOE +/- 5%) . You can find the entire poll here.
Obviously, that lead is statistically insignificant, but it is a continuation of the upward trend Halter has shown against Lincoln since the beginning of March.
Other notable results:
And, among likely general election voters (MOE +/- 4%):
Blanche Lincoln (D) 38
John Boozman (R) 58
Bill Halter (D) 42
John Boozman (R) 53
Other info from the poll can be found here.