Granted, this latest announcement is indeed a considerable leap even from the offerings of the SDK, since it looks to be aimed at the more non-technical user.
Its awesome that Valve releases their toolkit and I agree that most of the tools are pretty decent. Hammer (the level editor) is getting really long in the tooth though - it hasn't changed much fundamentally since Half Life 1 was released. And even then, it was pretty much just a third party editor for Quake (iirc - some of the details may be off).
https://developer.valvesoftware.com/wiki/SDK_Installation
Granted, this latest announcement is indeed a considerable leap even from the offerings of the SDK, since it looks to be aimed at the more non-technical user.