The Skeletal Spotlight shines this time on:
The Terminator Salvation poster
Interesting hints in the teaser poster above. We know that we will see John Conner as he begins the battle against mankind's dominator, Skynet and the Terminators which it develops to infiltrate the resistance. Presumably we will see the pre-Arnold-type models that they created first. The DNA strand in the eyes clues us in that the battle-scarred robot is looking toward using human biological material somehow, and we know what that leads to.
I think that with the star power of Bale that this has a chance of succeeding without Arnold's involvement... but eventually we are going to have to see the Sargeant Candy-based model if we ever witness the events of the final battle where he is sent back into the past, full-circle. Maybe they'll create a CGI version of him using Arnold's motion-captured performance and voice?