I seriously doubt we'd ever see anything like a Valve-branded Steam console sitting on the shelves at the local Target. If anything comes of this, I think we'll see something of a standardization of hardware formulas in an attempt to take some of the guesswork out of specs for gaming PCs. For better or for worse, Steam has ended up in the proverbial driver's seat of PC gaming, and it's in their best interest to take some steps to cut back on the confusion. Even as someone who (occasionally) builds my own PCs, I have to say there's a lot of confusing things to try to figure out these days, especially in terns of CPUs and video cards.
And no, I doubt we'll ever see Valve launching a streaming service; Why bother messing around with all the infrastructure something like that would take if most of your users are going to have systems with plenty of power to run the stuff locally?