The dual boot for me is working really well...now the envy of all my engineering work colleagues. When installing the first time, be patient, it stalls and it appears to lockup a few times but it is actually working fine.
Also, one somewhat odd issue, the screen would dim to a completely unusable level. I would have to reset it to fix it. It would work for 10 minutes or so and then dim again. You need to change the dim settings under Windows Mobile to anything other than auto. It now works great.
My GPS appears to be somewhat functional. It must be using cell phone or wifi info not actual GPS. This puts your position into within a quarter a mile or so.
Another annoyance, many programs are not viewable in Android Market. It appears that the most likely cause is the screen resolution is determined to not be compatible so it is not displayed. This could probably be changed in one of the configuration files.
You can manually download Pandora from:
http://pandora.android.s3.amazonaws.com/pandora.apk
It seems to work great, but you can't find Pandora under the Android Market for example.