In my current mode of creating all kinds of video files to test over AppleTV I ran across Hey!Watch, which is a site that lets you convert any video file format to any other video format -- pretty cool. The best part of the service is the "podcast" feed of your converted files that you can then subscribe to in iTunes so that the converted video files can be automatically downloaded and integrated into your iTunes library. There are limitation on the free version, but there's an upgraded version for $5/month. Basically if you don't want to dedicate a machine to DVD ripping and video conversion or don't have a machine to devote to the aforementioned tasks, Hey!Watch is certainly an alternative worth evaluating.
Note that there are other services out there doing much the same thing, but the "podcast" feature is not something I've seen on competitor sites.