He did kill himself, sort of.

The Vanilla Sky cast includes Tom Cruise, Penélope Cruz and Cameron Diaz in leading roles. An ambitious mix of genres, Vanilla Sky collapses into an incoherent jumble.

It reveals an entirely different orientation (which I will not reveal even here in the room), and, to be fair, there is a full explanation. The only problem with the explanation is that it explains the mechanism of our confusion, rather than telling us for sure what actually happened. He does have a choice of waking up or continuing the dream.

According to Cameron Crowe's commentary on Vanilla Sky, there are 4 different interpretations of the ending. Ending / spoiler for Vanilla Sky (2001), plus mistakes, quotes, trivia and more.
David decides to wake up 150 some years in the future. The ending of Vanilla Sky is actually pretty straightforward. He didn’t kill Sofia.

Crowe says it best in the Vanilla Sky production notes: “We constructed the movie, visually and story-wise, to reveal more and more the closer you look at it. Tom Cruise is having a lucid dream. (Original post by shes_ellectric) Open your eyes was made in 1997. #1 is that tech support is telling the truth, that 150 years have passed since David Aames killed himself, and that everything after his passing out on the sidewalk was a dream. Vanilla Sky (2001) : Movie Plot Ending Explained Vanilla Sky is a beautiful remake of the Spanish film “Abre Los Ojos” (Open Your Eyes) by Cameron Crowe. "Vanilla Sky" has started as if it is about David's life and loves. Vanilla Sky Critics Consensus. Everything that Tech Support says is true. So Vanilla Sky can be the diary of a madman, a downtrodden author's novel, a crash victim's coma dream, a playboy's twisting nightmare. The Literal View Vanilla Sky begins with a dream, as David Aames (Tom Cruise), playboy and heir to a publishing house, wanders an empty Times Square.

Built to confuse and provoke discussion, Vanilla Sky doesn t come with one or two definitive endings it s rather completely open-ended. Vanilla Sky is a remake of the Spanish film Abre Los Ojos (Open Your Eyes) by Alejandro Amenbar. What Does The Ending Of Vanilla Sky Really Mean? During the week he turns 33, NYC magazine publisher David Aames, a playboy who has strange dreams, spends a night of passion with Julie, "a friend he sometimes sleeps with," and a night with Sofia, a witty, knowing dancer with a Spanish accent - a night with intimations of love.