I haven't found a single free app (yet) that:
1) Converts source .mov or .mp4 content to .mp2
2) Creates the directory structure, directory and binary content files required by the DVD format
Of course there *are * free utilities that will do each individual step, in particular I found the file format conversion part of the process to be extremely variable in quality. AoA seems to do a good job on both, and of course, is very easy to use.