Well, here goes:
This is the script that I wrote for the mass BlueVM transfer (which went surprisingly smoothly, considering the mess that is HyperVM). It's all very hacky and consists of a bunch of different scripts, and mostly works. It's licensed under the WTFPL, so you can reuse it as you wish, but I have to stress again that you should not attempt to run this migration script unless you have full backups of all user and VPS data. Most likely the majority of people doesn't have a use for this (because after all, not many people use HyperVM anymore) but there may be that one guy that desperately needs a HyperVM migration script... so hey, why not?
I cannot guarantee that it will not fuck up your setup, especially if you are using anything that is not the newest version of HyperVM. This migration script involves setting up a separate VPS to handle migrations, and patching HyperVM panel code, so it's not for the faint of heart :)
Now that we've had all the warnings and red flags, instructions and code are included in the repository: http://github.com/joepie91/hypervm-migrate
Donations, as always, are appreciated. Support for this particular code is very limited, primarily because I really can't remember all the workarounds I had to make to get things to work properly. On that note, trying to use live migration will probably fail on many HyperVM setups, so the script will default to non-live migrations. If you really want to try live migrations, you can probably change it in the code... somewhere. The code you need for it is still in there, somewhere.