So you want to buy movies in an mpeg-4 video format so you don't have to buy movies in another format. OK.
First of all, nobody made you buy those previous formats, especially Laserdisc. That was about as standard as the MiniDisc. You're the fool who paid $100/movie when the VHS movies were maybe $20-25. DVD was a major breakthrough that fixed most of the VHS problems. It also helped make future changes, like Blu-ray, easier on the consumer. You don't have to re-buy all of your old DVD movies. A BD player will make those look better, and you can also purchase HD content on BDs. YOUR DVDs ARE NOT OBSOLETE.
If you think some computerized format will change that, you're kidding yourself. MP3 at 128k was an awesome format for about a decade. So instead of buying the uncompressed CDs, you did that. Now you've got iTunes Plus, which is twice the bitrate and an extra 30 cents/song. So that's another format upgrade that you don't necessarily have to do. Hell, I have some old-school iTunes videos (when they were 320x240). They look like crap on a full screen. I can't upgrade them to decent quality, and even if I could it would probably cost me.
If you want the latest technology, it'll cost you. At some point, audio will have some big change. DVD audio will probably be pushed at some point with "HD" sound quality, hopefully some of these advanced audio systems like Dolby Digital and DTS. CD audio hasn't gotten any better since the format was introduced about 20+ years ago, so we're semi-lucky that hasn't changed.
