Right now, the new "Terminator" movie announced by Annapurna Pictures and Skydance Productions for a summer 2015 release date is a total mystery. We know that it's a "reboot" and the start of a "stand-alone trilogy" that Arnold Schwarznegger might star in.

That being said, a number of rumors and the scant parameter we do know of limit the possibilities of what the new "Terminator" trilogy can be. Assuming that Arnold is set to return in a lead role, this is what we (think we) know so far about the next "Terminator."

Arnold has to be human.

Schwarzenegger, like all mortals, has aged over the years. Though he may be in great physical shape given his age, 65, Arnie isn't the young man fresh off of the Mr. Olympia circuit that he was in 1984, when the first "Terminator" hit theaters. If Schwarzenegger was to step back into the role of the T-800, the robotic killing machine might look curiously haggard, as if he had just finished two terms as governor of California and gone through one of the messiest public divorces in history. "Dude, Terminator looks rough!"

He has to be the model for the T-800.

If Schwarzenegger's character is human, how do you explain his uncanny resemblance to the Terminator that hunts Sarah Connor in the first film and protects her son John in the second? That question would logically be a central element of the movie, which would reveal what this guy, whoever he is, does to become the image of killing efficiency.

This deleted scene is getting reconned.

The first step in establishing a story for a human character played by Schwarzenegger is to ignore the existence of this deleted scene from "Terminator 3: Rise of the Machines." Aside from being an outright joke, the story of Sargent Candy closes off that narrative vein for further exploration, because who wants to see a movie about that guy? And not that it needs any more arguments against it, but a Sargent Candy movie would rule out using Schwarzenegger's real voice, which -- correct me if I'm wrong -- is the whole point of a Schwarzenegger movie.

It's either set it in the past...

The most high-profile rumor to surface since Annapurna and Skydance took over the rights to the franchise originated at Examiner.com, which claimed that Dwayne Johnson was wanted for a role. The site reported exclusively that Johnson would play a Terminator sent back to the 1940s or 1950s, traveling further down the Connor bloodline in an attempt to stop John from being the ultimate robot defeater he becomes. Schwarzenegger would play the man who stops the futuristic assassin using period-appropriate technology, thus impressing the robotic overlords and becoming the model for the T-800.

This option is slightly more problematic because the timeframe would make it less "stand-alone" -- as today's press release indicated it would be -- since it would have to come between "Terminator 3: Rise of the Machines" and "Terminator Salvation," when the Arnie T-800 first showed up. This also narrows the window for the trilogy significantly, making a future-set, Schwarzenegger-centric less likely.

What do you want to see in a new "Terminator" movie? Let us know in the comments below and on Twitter!