Many people here have posted thoughts along the lines of "I want an actual box, CD/DVD, etc" and will buy the game via the regular old brick and mortar retail channel.
I'm one of those brick-n-mortar guys not so much because I like the idea of having an actual CD--though admittedly it is a big reason--but because I don't want to have to install Steam for all the typical reasons listed. However, given this latest news, if Steam were to provide some way to burn HL2 (and all their other games) to CD after downloading it would go a long way in convincing me (and potentially many others) to purchase Valve products over Steam. I've been following the threads on HL2 and Steam for a bit now so if the ability to burn a game to CD is available in Steam please let me know. Having a CD and knowing you don't have to spend the time downloading the game again after your HD crashes is worth the peace of mind, in my opinion.
"Worry is only anxiety over something that may never happen." -V2