I know everyone loves Valve, but it feels super weird to be celebrating a monopoly so much and so ferociously. (I know Steam isn't a technical monopoly. We don't need to have that discussion)
Gaben is old, and he's gonna retire. It'll likely be a lot sooner than anyone here is comfortable with. When Valve gets sold, or even when gaben isn't in total control anymore, things are going to start changing, and there isn't going to be a healthy, diverse marketplace to soften that.
There is a very good chance that the PC platform will be a really horrible place because of the lack of consumer choice in which they can purchase and play games.