I just read Easy, Efficient Hi-Def Video Playback, and after reading through all the "Convenient" steps required to rip and watch a movie, I'm left shaking my head.  This is more convenient than putting a disc into a player?  You also lose DVD chapters and menus this way, so good luck watching part of a movie one night and picking up where you left off later.  I guess that's why I still prefer Tivo to building my own MythTV/DVR box.  By the way, we watched our first Netflix "Watch Instantly" movie this weekend, and I was impressed.  I had to queue it up via netflix's web site, but it streamed to the TivoHD with no problems and we could pause/resume/rewind just like any other TV show.  It doesn't have chapters either, but if you stop/pause it remembers your place in the movie.  If you google, you can get some pretty good deals on new or refurvished TivoHDs.

Unfortunately, on a dual core Athlon -- even overclocked to 2.3 GHz -- the Planet Earth rips are on the ragged edge of playability under Windows Media Player. CPU usage is well north of 80% all the time, and some peaks at 100% mean video stuttering and sound breakup at least a few times in each episode. This is unacceptable.