Windows 8.1 Update 1 Leaked

The leak:

Paul Thurrott and Mary Jo Foley articles:

Short version: There's nothing interesting in the build yet. It will be revelead at Build 2014.

Will it bring more API parity?

Will it be a Service Pack?

When will WinRT==WinPRT (or just WinPRT=WinRT)?

What will it mean for developers?

Will we see some WP8.1 improvements as Cortana or Notification Center?

Will first party apps be updated?