Linux on the "commoner's" desktop is not likely to happen. The PC industry has tied its fate to Microsoft and it is even less likely to try something stupid in lean times like this.
The target markets in the announcements are quite descriptive - these are all people who can afford something that fits their very specific needs and see Clippy (and its more voluptuous Cortana incarnation) as a parasite which gets in the way.
Disclaimer - the last Windows desktop in the house was wiped in 1997 and I presently have 5 (a personal per head + 1 shared) Linux desktops, 4 Linux laptops, 3 Linux STBs and 2 RPi based controllers. All of that is running Debian. Based on running that Linux is fit for purpose to be a desktop for Joe Average User 99% of the time.
The problem is not in fitness for purpose. The problem is that the PC industry will not accept it. It has become dependent on the upgrade cycle brought by MSFT OS releases and even the abject failure of the last 3 releases to bring new PC requirements is not likely to wean it off this dependency.