New Steam Update!

That sounds too good to be true. It probably only involves "old" Steamwork titles.

EDIT: Weren't old source games once sold on disc. That's probably what they're referring too.

Maybe you can install games from disc, but only if you have already the game on STEAM, I suppose.

Earlier in Russia were possible to not download the game from steam, but install it from disc and only then you have to download the latest steam patch.

Or maybe just using the physical copy as source to install instead of downloading. Not everyone has fast Internet…

It's probably something along the line of the counter strike source disc I have from the late late 90's close to when steam first released, was probably having problems being recognized and now it is fixed.

I would say not, this is most likley due to the steam streaming beta, they announced that you can "add a none steam game to your library" and then use steam to stream it to another pc/device within your LAN so it's likely a cleanup to allow steam to interact with the games pre install rather than just post.
Though EyEBURNeRs theory sounds probable.

This reminds me that I should open Rogue Warrior (retail) and use the steam code before it expires :\