I don't think that's a magical bandaid that will undo decades of branding
I'm sure somewhere, someone at Nintendo said the same thing when MS stepped into the ring.
I think the biggest draw for current PC gamers, which are a very different core group than mainstream "gamers"... is the game streaming, and the controller. This is of course assuming the controller natively supports XInput and I don't have to use x360CE on every lazily ported game anymore.
How did Sony get access to utilize DirectX on a closed, directly competing platform? Valve will need to take a similar step to make their machines truly viable and reduce fragmentation among developers.