I use this website
http://www.hardocp.com/ for keeping up to date with computer hardware and gaming technology related stuff, others might find it handy too.
If you search around there you'll find some info on what DirectX 11 brings over previous versions. There's an interesting bench-marking program around somewhere that people have made video's of to show what's going on...
Okay, here's one, but I'd suggest turning the volume down and jumping to about 1min in, and there's more to DX11 effects than what's shown here -
Just had a quick look in the forums and saw links to these two short video's as well. These are clips from a real-time simulation someone made using DX11 -
There'll be fire and smoke in SOW right? Well...
How about water?
Is it possible? Who knows, who knows...Shrugs shoulders, moves on...
As far as choosing between a DX11 capable card or not, I would, but not just for DX11.
All the latest 5XXX series ATI/AMD cards are DX11 capable anyway (but not the 4XXX series) and the new as yet unreleased nVidia cards will be too, so by the time SOW comes out (later this year?) DX11 capability will be the default, even if hardly any game designers use it.
At the moment, I think there are only one or two games out that actually use DX11 effects, so as usual, it's one of those wait and see things. And as usual, in the meantime there's a lot of hype spun around it all. I've heard that technically speaking all the DX11 effects can be done in DX9 and 10, but it takes more work behind the scenes and would kill your framerates, while at the same time, the DX11 way of doing it is still pretty hardware intensive (thus requiring the latest cards).
From what I've seen, SOW could make use of DX11 in ways that would almost add up to something like the 'perfect' mode we have now in the IL-2 series, only more so, and I kind of hope they do, even if just as an option, as something we'll be able to switch on in the future when the hardware catches up. (Sound familiar?)
Les.