Wow, the amount of misinformation in this thread is staggering.
Let's start with the incorrect info from SCI FI Wire itself, which no one who picks up their item seems to fact check: UA has not taken over MGM. MGM is the majority stakeholder in UA.
Continuing: The only reason Whedon met with Cruise is because Mary Parent, head of MGM, moved the film from MGM proper to UA in order to take advantage of UA's pool of money to make movies. MGM itself has more movies on its slate than money to make them.
Cruise heads up UA, and so in essence this was just Whedon meeting his new boss. Pre-production and staffing up on Cabin was well under way before this meeting ever happened.
Cruise is not in the film.
And the "horror movie to end all horror movies, literally" line with which Whedon first announced the project, if you're at all familiar with how Whedon works, inevitably means something very specific, and what it most definitely does NOT mean is that he's saying all other horror movies have been, and will forever be, crap compared to his.
Carry on.