I don't see Windows 10 affecting Linux/BSD users, it's just a windows 8 with a start menu and multiple workspaces. I think things will remain the same, the ones using windows will remain using windows and I don't see Linux/BSD users adopting Windows except if extremely necessary (Adobe Tools, etc).

It's normal that the home computer sales are dropping, you can run most recent operating systems in a 2008/09 with a good performance for the average user. Also, a lot of people that used computers just to navigate in facebook and make calls in skype opted for tablets.

I don't think that Windows 10 will make some kind of "revolution".