According to the Northwest Indiana Times:
The Times has learned from a source close to the Alexander camp that the fight has indeed been agreed to and that it will be contested at a special heavyweight catch weight of 215 pounds on "The Ultimate Fighter 10 Finale" on Dec. 5 at The Pearl at The Palms in Las Vegas.
This rumor has been going around for a week or so, but it sounds about right. I wasn't sure if Kimbo would be able to make 205, and Alexander probably walks around at 215 or so. It's a fight that could pay huge dividends in that both fighters are relatively popular. Alexander instantly became a crowd favorite after bursting on the scene at UFC 71 destroying Keith Jardine after coming from relative obscurity. However, he's lost his last three inside the octagon and took a fight outside the UFC to pick up a much needed win. This fight will not goto the ground, so that increases his chances of winning. Of course, everyone knows who Kimbo Slice is by now and he's single handedly responsible for the successful ratings of TUF 10. A win over Alexander would give him creditibility amongst casual fans, and the opportunity to appear on a UFC ppv which would be a gold mine for the UFC. Who you got in this one?