On the download page it specifies that while the file contains no DRM, your purchase information IS embedded into the file.
I'm betting that anyone that's downloaded it and put it on megaupload either hasn't read that, or is willing to have a great big red arrow pointing to his name and address, tagged with "I DISTRIBUTE STUFF ILLEGALLY".
I'm aware that the info can probably be stripped out, but hey who read the fine print anyway, so a few a bound to get stuck in the booby trap ;)
Anyways, I decided to put the 2$ on the line and download the full version, gonna burn it as a DVD video to see if it passes the test as a valid replacement for a DVD. I'm also interested in the PSP version: thought I usually encode my own, having it provided for me might not be such a bad thing.