It was said at Eastcoaster that the only reason they went with the Thunderbird layout for Evel is because they only had something like 3 days to come up with a layout to sign the contract (it's been a while since I've seen the video where they explain it completely). The Thunderbird layout just happened to fit in the site SFSTL wanted to use, so really it wasn't SF just wanting another clone, it was a matter of coincidence and being pressed for time. There is no "clone of choice".
As far as the Terminator theme goes, I've thought it was a joke since it came up. If it isn't, I don't think it will be a big deal at all, probably nothing more than the paint job on the trains and perhaps a few things at the entrance. But I'm sure the ride itself will be very traditional looking, which is a good thing IMO.
Edit: Here's the video explaining it:
http://www.youtube.com/watch?v=2F65LZYHSKQ