While there has yet to be a formal announcement that Justin Lin is indeed directing Terminator 5 but he's already giving hints who he would cast in the film. Lin mentions to MovieHole speaking with Vin Diesel about the Terminator mythology and would like to use him in the film. While I doubt really care for the Fast & Furious franchise Vin is a decent actor when given the right material and genre. I'm really excited for the new Riddick film and he is gruff enough for the brutal world of Terminator.
“We’ve talked about the mythology (of the Terminator series...)([pause) he’s a great guy and a great actor. I really like working with him so anything I do I usually talk to him about. Sometimes we even talk about going back and doing a little indy movie,"
My only problem is with Lin as Terminator won't have the distraction of pretty ladies/cars which is the main forumla of his previous films. Here's hoping it doesn't become a total mess and we have yet another reboot/remake on our hands. The only good thing about this is that Lin has been rumored to have talked to Arnold about returning to the franchise. I'm unsure how he could fit in the film unless he's a human character but it would be interesting to find out.