Windows Store Apps
As of May 2012...
There is apparently no support in Metro for Bluetooth. For instance there is no access to System.Net.Socket.Socket which is used with the Microsoft Bluetooth stack for comms, nor is there access of course to the Bluetooth Win32 APIs.
Neither are there any APIs in WinRT for Bluetooth. In ProximityFinder classes a proximate connection can be made using NFC ('tap' gesture) or Wi-Fi Direct (peer browsing), and optionally a socket connection can be opened for longer term use using Wi-Fi
Direct, TCP/IP, or Bluetooth. But there's no way to make a separate Bluetooth connection apart from that.
Looks pretty bad. :-(