House is dead, Wilson creates him for support.
House imagined a relationship with Cuddy whilst on drugs and self pity. Wilson dies the same.
House dies in the explosion in front of Wilson. During his eulogy Wilson hopes that his friend still lives. He hopes that its all an elaborate trick, another prank by House.
But it isn't. His friend is dead and Wilson must face his own imminent death alone. In his despair and loneliness Wilson recreates his friend so that he can find the strength to continue.
House's last words are,"I'm dead, Wilson. How do you want to spend your last five months?" Followed by,"Cancers boring" as Wilson rides off.
This show is Everybody Dies and its true.