The PC version of Halo 2 had the option of letting you play straight from the CD/DVD while it installs in the background. Looked like a great idea to pop in the disc and start playing. Whatever happened to it and why it didn't caught on? Too much differing hardware (although they could just slap on a "minimum read speed" requirement in there) or just unnecessary hassle?

I've never heard of that, it sounds awesome. I guess I have kind of always wondered why PC games make you wait so damn long before enjoying your game, so i'm not sure why that wouldn't catch on. 

" The PC version of Halo 2 had the option of letting you play straight from the CD/DVD while it installs in the background. Looked like a great idea to pop in the disc and start playing. Whatever happened to it and why it didn't caught on? Too much differing hardware (although they could just slap on a "minimum read speed" requirement in there) or just unnecessary hassle? "

It's a novel concept, but really, can people not wait 5 minutes for a game to install?

The idea seems pointless now that digital downloads for PC games are so prominent.  However if they shifted this idea to digital downloads it would be brilliant.   
 
I am sure there are other examples but this first happened to me when downloading Lord of the Rings Online.  The game is a fairly big download but to get you going as fast as possible you can start playing the game after only about 1gb of downloading.  You start playing while the rest of the game downloads in the background.  
 

@ajamafalous

" It's a novel concept, but really, can people not wait 5 minutes for a game to install? "