I was able to successfully get my internet sharing to work on Windows 7 using my HTC Windows Mobile Phone via USB. I have not tested bluetooth dial up yet. Although in the Car I found that Internet Sharing is more stable via USB than via bluetooth, both do work however..at least on LINUX.
In the car, atleast with my own experience, Internet Sharing with my Mobile Phone is more convenient and stable than using Wifi. So I am happy that this feature is working great on Windows 7. Either way at least I have a backup internet connection option, which is always great and convenient.
I am writing this post using my Internet Sharing Connection
I forgot to add that this also works while using Centrafuse.