Some people think Microsoft will show the next version at MWC in February and that it will be again based on the 6.x operating system. That 6.x version is called 6.5.3 and has already quietly been released to manufacturing in December of 2009, according to a reliable source. There will be no announcement of this version. It will simply show up on shipping products whenever manufacturers are ready. You’ve already seen plenty of videos of leaked 6.5.3 ROMs with the Start menu at the bottom, the thinner notifications bar, and user-arrange-able Start menu items. It’s being billed as an even smaller upgrade to to 6.x than 6.5 was even though many of the UI changes look pretty significant to us. So keep an eye out for actual devices coming soon… like the Garmin-Asus M10 which has just been announced for pre-order.