I have a good feeling that HT will put out a new endoskeleton, but from T1. If that does happen... hello Terminator Battalion!
I think it's more likely to make one from T2. If they release a new Endo from T1, it'll be like re-releasing it almost. A different movie is the only excuse not to piss off hard-core collectors. I'm hoping for a new classic shiny Endo to be made as well, so I can finally have more than just the T-600 and T-700. I need to have at least three figs from each line I collect, otherwise it's just not enough .