Not too bothered by this, to be honest. Mir, much as I like him, was going to go down hard to Cormier (JDS style). I really don't feel as though any part of that fight would have been competitive. It's only a bummer in the sense that the organization now has to scramble for a replacement.
Someone mentioned Fabricio. Could be a decent fight. Roy Nelson would certainly make it a show, but he's obviously tied up.