If Cruise was there for only one day it is unlikely he is in the movie. Unlikely but not impossible. Let's just hope not.
Of course, because as we all know, Trekkies are the most self-righteous and snobbish when it comes to the Trek name they think they own, and big name actors are just the worst thing that could ever happen to Trek.
That's why when there was all this Gene Hackman talk, they made the right choice with Anthony Zerbe. And who needs Sean Connery when you can have Laurence Luckinbill?
And how many days do you honestly think it look to film all those 30 second cameos per actor for the last Austin Powers movie?