The instructions and documentation for manually moving your crap to a new XBox are somewhat vague and conflicting online (or perhaps I'm just dumb). Some files cannot be copied (like profiles and certain game saves) they have to be "Moved". So I filled up a 8 GB Patriot USB drive last night and figured the Remove Drive function that they have there was the proper way to safely unmount the drive (btw, you're supposed to turn off the XBox), so with no warning or confirmation it states "Removing all XBox files from USB device" and it deletes them.

Of course, the delete was fast, so it likely just wiped the contents table. On a normal disk I know how to recover this kind of thing with about half a dozen utilities. But I have no idea what kind of signing or crypto crap might have been fully wiped.

Live profiles are easy to recover, but some of the save games that couldn't be copied would just be gone (some are games I play with my daughter a lot, she would be very frustrated to have to start over).
---------------Hours later after phone support-------------------
Does anyone know a utility that can actually restore the files on these?
Well, don't bother calling support over this. Basically you'll spend 2 hours explaining you don't need help recovering your Arcade games and DLC files, just local files, and when they get it they have no solution.

Actually they seem to know the f-ed this one up, they are working internally on a revamp on how this works since people are losing their crap all the time.

Moral of the story, pay 20 bucks for the transfer cable, it has a chance of working correctly (and I think it has a recover from last stop point function, so if you have 100 GB worth of stuff and it gets interrupted you lose nothing and don't have to start over).