We've discussed the new Windows Phone 7 and whether it was going to be an appropriate OS for a Data Collection device.

The latest information we have is that there is going to be a separation between Windows Phone 7 and the traditional Windows CE and Windows Mobile 6.5 line. Here is a post from Microsoft describing the changes.

The bottom line appears to be this:
Windows Phone 7 is based on the Windows CE 7 core, and is aimed at Consumer devices only.
Windows Mobile 6.5 will still be available, as will Windows CE, and will be used on Data Collection devices.