PCmover Windows 8 Beta Assistant allows users to move selected programs, files and settings from a Windows 7 or Windows 8 machine into a new machine running Windows 8. Laplink has had an earlier version that was very useful in Windows 7 migrations from XP. You can watch a short video of mine here that describes the process.
It will work with the Developer Preview of Win8 as well as all of the upcoming beta releases and release candidate builds. Its only limitation is that both the source and destination machines need to be running 64-bit OS's.
Like earlier versions of PCmover, programs that had copy-protection or use DRM will need to be uninstalled before doing the migration. Anti-virus software isn't migrated either, because these are typically tied very closely to the particular OS version. The software will also ship with selected Intel motherboards. There are several different versions of PCmover that range in price from $30 to $60, depending on the features involved. But you can download the Win8 migration version now for free.
If you have to migrate your older Windows machines in mass quantities, there are other tools out there that are more suitable. But for less than 10 PCs, or if you want to see what kind of problems you are going to experience with Win8, PCmover has a good approach.