Look at it!
Spelunky is coming to PS4 with 1080p graphics, social features, leaderboards, and replay uploading. Yes.
Derek Yu said that they want to support the sharing and streaming culture, so they're asking commenters on the PlayStation Blog to weigh in with anything they'd like to see added to the PS4 version.
And yes, there is Cross-Buy support, so you'll automagically have the PS4 game when it comes out if you already have the PS3 or Vita versions.