Well, for gamers in particular there is some incentive upgrade. Windows 10 supports DirectX 12... older windows versions do not. Which in theory can mean improvement in some games.
Unfortunately real work testing has shown no significant advantage as of yet, and it will likely be another 2 years before we see games actually make use of it.
I also would not be surprised at all if MS were to extend the upgrade period indefinitely... the more people they can get to upgrade the cheaper it is for them in the long run, vs supporting older OS versions.
Ha, now you're speaking my language.
This is exactly why I installed W10 on my new laptop. DX12 is the future, no doubt.
I wouldn't say 2 years, though. You can grab Unreal Engine 4 and start writing DX12 shaders (or just run DX12 capable demos) right away - they've been out for some time now.
But yeah, game development is a tricky process because you can't just re-write your rendering code mid-production, so only the games that are currently in the stage where they can still incorporate DX12 will do so, but they'll be out in in maybe a year. DX12 development kits and documentation has been out for long time so I don't think we'll wait too long.
What I'm most happy about is the multi-GPU support, check this out:
GeForce + Radeon: Previewing DirectX 12 Multi-Adapter with Ashes of the Singularity
Long-story-short, you can use any GPU to add more performance to your games. Any Intel Core owner already has an Intel HD GPU onboard - you can use that in parallel to the primary GPU you are using for gaming to boost your performance, and not by some marginal degree, either! Unreal Engine "Elemental Demo" has been used to test the multi-gpu setup earlier, and difference was 35 FPS -> 39 FPS.
And that's
before you start taking the actual advantage of DX12 into account: the CPU overhead reduction for draw calls.
Now, I'm not expecting games are suddenly gonna run 60FPS flat on ancient hardware - no hardware manufacturer wants that, all I'm saying is that we can pretty much expect games to look like pre-rendered trailers, on normal non-cutting-edge hardware.