According to a report by Oklahoma City's News 9, as well as other sources, Speaker of the House T.W. Shannon is expected to resign his post in order to focus on running for the U.S. Senate seat being vacated by Dr. Tom Coburn.
It appears that the race to succeed Shannon as Speaker has already begun. State Reps. Mike Jackson, Scott Martin, and Jason Nelson are rumored to be seeking support from their Republican colleagues.
Update from the Associated Press:
Several House Republicans told The Associated Press on Thursday that Rep. Mike Jackson of Enid and Jason Nelson of Oklahoma City are working to secure votes in case of a potential speaker's race.
Nelson and Jackson both confirmed to the AP they would be interested in the post if Shannon steps down.