BrightHand quotes a Microsoft spokesperson stating:
We recently gave Windows Mobile device makers the final updates to our new browser. It’s now up to our partners to roll out Internet Explorer Mobile 6 on their handsets; we’re expecting some of the first phones with IE6 to be available in Asia and Europe by the end of calendar year 2008, with U.S. offerings to follow.
Unfortunately, it looks like existing Windows Mobile handsets will not receive this upgrade. Customers on recent HTC devices will not be annoyed too much (they get Opera for free – everybody else will be less than happy.
As Microsoft gives up a large part of the market by not supporting legacy devices, I consider it highly possible that an aftermarket upgrade of some sort will become available.
So: stay tuned for further info as we get it!