I don't think that it's going to be Cromartie because they upped him to regular. Though I wouldn't mind being wrong. I like Ellison so I wouldn't mind him staying around. I doubt that the new character of Catherine will be killed quickly because her company is involved with Skynet's creation.
Also, they're doing something I like with this series in terms of script delivery. They're only releasing the scripts to the actors in small intervals (not the entire episode script) to keep spoilers to a minimum. Good for them, bad for this thread...