Rumor is he would just fill in the 10 dates on tour.
Axl is one of the best rock singers and has covered some AC/DC songs with GN'R before. I think he is no longer as easily agitated as he once was. Once Chinese Democracy finally was released he seemed to enjoy music again. To be quite honest he is likely one of the best people to fill in and he fits in with the band better than say Adam Lambert with Queen.
Plus, with Slash and Duff joining Guns N' Roses we know that this is not a long term thing for Axl.