Being at TechEd in North America last week it seems that ACT 5.6 was released on Monday last week. Among the improvements are tools for migrating to the 64-bit platform, including a 64-bit version of the Compatibility Administrator.
The assessment overview is something that also has been improved and I strongly recommend you to download and intall this tool if you are making an inventory for upgrading to Windows 7.
Download at MS Download Center.