As far as I know, the 360 will not play burned disks without a custom firmware update for the optical drive.
If you are talking about the new feature that came with the new 360 dashboard that allows you to install games to the drive, yes it does work. I have one and I do it. However, you still have to put the disk in to play. It just plays it from the hard drive instead. This helps the game to run faster and eliminates the sound from the DVD drive running. Also, note that it does take a lot of hard drive space to install games.