From a post on Xbins.org is the following from Team PI:

So you've seen all our raw dumps? but what can you use them for?
Nothing in their current form, yet! - But here we go with a nice extractor tool so that you can extract the dumps and check out the files, we even decided to release the source code, so that you can figure out the filesystem and make even nicer tools and clean up our horrible looking code, cause we are lazy and old!
Usage: extract360.exe gamename.360 [wildcard]...
For example: extract360.exe pi-nfsmw.360
Sit back and relax, and enjoy, these xbox360 games are quite large!

And a note to the tech guys: Yes, once you get past the protections and down to the raw bits on the disc, its just the standard xboxdvdfs, however the offset and layer breakpoint are different!


Interesting huh?

X-S does a good job of explaining what this all means as follows regarding Game Dump Extractor V1.0:

They also released an open-source tool to extract these releases (basically it's an 'x360-ISO extractor') so you can check out the files in the image. It will NOT work on original discs as a PC DVD-ROM can't read those. Just like the original Xbox (xdvdfs) the 360 does not use the ISO9660 or UDF filesystem for the content on game DVDs. This tools allows you to extract the files from an image in the 'Xbox 360 DVD file system', it does NOT bypass the protection that prevents you from reading an original Xbox 360 disc on your PC.
(spelling errors corrected from original text)