HL2 and the Future of Game Delivery?

Url: http://steampowered.com
I purchased Halflife 2 directly from Valve through their Steam software.  This allowed me to download the game, but not play it until release.  Since today is release, they unlocked it.  Why isn’t most software like this?  Valve does better because they cut out the middlemen and keep the majority of the profits, I get the game as soon as I want it (if you buy now, you can play as soon as it downloads), and less physical packaging to dump into landfills/recycle.  It is just a streams of one’s and zero’s after all.  I hope this becomes a trend because I love it!