I am waiting for such a SIP for WM devices for long time... since I gave up my S/E P800 and got a HTC Magician...
Since many years ago already there was SeeTru keyboard for UIQ, see here:
While UIQ is almost dead already there is still hope for WM ;-)
Lets hope someone might develop such a SIP. IMHO it would be a 'killer app'.
Surur, are you the same well known Surur from other communitiers? If so, you might further advertise this idea. Someone might here to your words.