(Not sure if I should post this here or in 3D forum)
Huge changes for Source Engine modders:
http://store.steampowered.com/news/10962/
- support for Linux and Mac builds now

- Hammer comes along the games, instead inside the SDK
- the SDK Launcher is going to disappear
- support for Oculus Rift
I find a bit odd the choice to go for a "localized" version of the tools in each game; I am expecting that for Source 2 they will approach the toolkit's distribution in the same way Epic and Crytek do.