If you've been disappointed by how recent PC versions of Call of Duty haven't taken advantage of your ridiculously alien-looking hardware, then Treyarch has some good news for you.
Call of Duty: Black Ops II will run naturally on DirectX 11. Not only will it take advantage of technologies such as tesselation, but it'll also be optimized to run on multiple threads bringing a strong balance of performance and quality.
In terms of how it compares to consoles the following was posted on Treyarch's community site:
Black Ops II PC features enhanced lighting, shadows, antialiasing, bloom, depth of field, ambient occlusion, and other enhanced effects that are still in the works. And the game can run at higher resolutions and higher framerates on the PC.
As a result of Treyarch's push to support DirectX 11, Call of Duty: Black Ops II will not support Windows XP. If you're still living in 2001 when Bush became president, then you may want to look to upgrading your PC or buying the game for a console.
To sum this all up, if you have a PC that can run games like Guild Wars 2 and Diablo III, then you're probably going to want to purchase the upcoming Call of Duty for it. That is, unless split-screen is important to you. Significantly better visuals and higher performance will make this the first Call of Duty to show why current-generation consoles have fallen way behind the times.