Now that it is fairly well established that Ryan Reynolds is not a movie star, why would you reboot a franchise around him?
Reynolds should be looking for work with actors that can make him look better. He needs to do some smaller roles that will help keep him out in front of people. It is too soon after the Green Lantern debacle to start thinking about another franchise.
(Unless, of course, all they want to do is make a quick buck with a Highlander knockoff for a really low budget and the only actor they can get is Reynolds--then I could see this working, because, well, it just won't work.)