Done by the Daily Oklahoman, and done extremely crappily (300 phone calls, 200 online, they say the MOE is 4.4% for the general questions, and 5.7% for the primary questions, i'd wager it's at least 5%).
the articles are here, here, and here.
The guts of it is that the Republican primary is going to be extremely close between plutocrat Kirk Humphries and Dr. Tom Coburn. Both are at 21% now, according to the poll, with moderate Bob Anthony's at 11% and wingnut Linda Murphy at 5%.
Coburn beats presumptive Democratic nominee Brad Carson 41/39, but given that the Oklahoman is ridiculously right wing, and the poll is very suspect, i'd say it's more likely that we have a slight edge.
Oklahoma is a red state, however, with Bush at a 53-34 against Kerry. still, 54% for a dead red state isn't that impressive for Bush.