Simon Pegg has become the first cast member to comment on the new movie title by tweeting (@simonpegg) that "Star Trek" is a verb, not a noun. He boldly confirms that the title is "Star Trek Into Darkness".
Except it's still a noun, unless that's interpreted as an imperative: "Star, trek into darkness!" It's just a noun that has a prepositional phrase added to it.
I star trek into darkness.
He/she/it star treks into darkness.
We star trek into darkness.
They star trek into darkness.
Now it's a verb.
Of course "Star Trek" is a verb. We already knew that from "Star Trekkin' across the universe..."