Here is new version of VHD Attach.
Due to popular demand, you can now change drive letter from within application. While this is not strictly VHD related task, I got it as suggestion from enough people. See, if you ask for something enough times, it is done eventually.
This version should also work on Windows 8 but do notice that there was no extensive testing. Probably new version will be out when Windows 8 is officially published.
Excellent work!