Old school fun
Foreboding thoughts aside, in the here-and-now Windows 8 is largely indistinguishable from Windows 7 when running non-Modern UI apps.
Your games will still install, full-screen and play. You won't see any differences. You're not going to be locked out of anything.
Barring any compatibility issues, nothing that runs now isn't going to work after you install Windows 8.
The first big concern for anyone who doesn't want to upgrade should be DirectX 12.
Microsoft isn't afraid to use gaming as a reason to force an upgrade, and this will almost certainly be for Windows 8 only - just like DirectX 11.1 currently is.
On the face of it, it might not seem a big deal. Not that many games support DirectX 11 right now, and the majority of those are quite happy with DirectX 9 or 10 if you don't have the hardware or oomph.
DirectX 12 may well be the same - extra features worth having, but not something you absolutely have to upgrade for right now.
We're on the edge of a new console hardware generation though, which will undoubtedly shake things up.
Controlling the Xbox 360 hardware, in particular, gives Microsoft plenty of scope for making DirectX essential for the next wave of AAA games.
It's not like it hasn't tried something similar before. If you wanted Halo 2 on PC, you officially had to buy Vista... even though modders quickly discovered it ran fine on XP.
Even if games will run on earlier versions of DirectX for compatibility reasons, simply offering parity could be a crucial weapon.
Fighting the future
Threat or not, nobody is seriously suggesting boycotting or not supporting Windows 8. It's going to sell far too well for that, especially when the threat is frog-in-hot-water level fear rather than a specific thing to rail against here-and-now.
If that ever happens, it'll be because Microsoft has dropped the portcullis and locked the doors, and developers have to decide whether to be in their store or not.
The only person seriously talking about challenging the status quo, rather than simply complaining about how it's changing, is Valve's Gabe Newell, and even then it's Plan B.
"We want to make it as easy as possible for the 2,500 games on Steam to run on Linux as well," he said at the Casual Connect conference back in July. "It's a hedging strategy."
This has fuelled much speculation about a full-on Steam box powered by Linux, as well as a massive boost for Linux itself.
Whether or not it actually happens, of course, remains to be seen - and Valve isn't exactly known for its speedy development.
In short, if you want to play PC games, you're going to be doing it on Windows for the foreseeable future. Whether you do it on Windows Vista, 7 or 8, however, remains your choice.
There are no big exclusives to worry about, and you're highly unlikely to notice any differences with anything until at least DirectX 12.
Don't be afraid to upgrade, but don't worry about being left behind either - at least, not just yet.