Allen's entry further divides a field that already had no clear frontrunner. None of the announced candidates are well known or have prior elective experience. Unless a higher profile candidate (say a Jim Bennett type) enters the race, the election will almost certainly revolve around each candidate's home base.
Samantha Shaw is the Montgomery County GOP chair, Wes Allen has ties to Tuscaloosa, Chess Bedsole's roots are in Mobile, and Tripp Skipper is based in Auburn. Assuming no more candidates emerge (which is no sure bet) the race will be won by the candidate who can secure his or her base and make inroads into the rest of the state. This race seems headed for a runoff, as there is no reason to expect one candidate to run away from the pack.
If I had to guess I'd expect a Shaw/Bedsole runoff, but it is really too early to try to handicap such a fluid race.
Oh, and the Democrats still don't have a candidate.