My fear for Dx12 is that it is going to be windows 8 only, for arbitrary reasons. Microsoft will think it's a great way to monetize the development. But they'll actually delay market penetration because every game would still need to support windows 7 through dx11 for several more years.

If they are smart, they'll release it as a windows 7 / windows 8 "service pack", but require the user to authenticate online first. It'll still hurt acceptance, but it's much harder for the player to argue "I pirated win7, it should still work" rather than "I bought win7 18 months ago, now it's useless". Unfortunately, MS are hell-bent on phasing out win7 as soon as possible.

The reasons are quite reasonable. Mainstream support for Windows 7 ends January 13, 2015. After that only security fixes for 5 years. They won't release a major feature couple months before support for the OS ends.

Windows 8's market share has ben declining steadily since December (source: statcounter). Windows 7 is refusing to drop.

I don't know whose brilliant idea it was to put a gesture-based OS on a mouse-based platform, but Microsoft is going to need to up its game or else create an ever-larger oppourtunity for competitors.