Hi - yeah, just read about the MicroKeys "Air" (wireless Bluetooth MIDI keyboards from Korg). I'm especially curious how latency on wireless BT will be - whether it will "feel" just like playing a wired keyboard in terms of how quickly you hear sound when you play a key ...
I have a bi-directional bluetooth midi interface by Quicco Sound.
http://www.quicco.co.jp/ It works fine on a keyboard, but just could not handle and get jammed within a few seconds when my Roland midi accordion generated so much midi data on multiple MIDI channels.
The Korg bluetooth midi keyboard is going to be handy to play some nice sounds in IOS devices and even play the only IOS arranger MidiBand,but I don't think bluetooth midi is supported natively by Windows yet.