Sound spatialization algorithms are not something the average gamer thinks about. It's a Carmackian phrase; I can already see your eyes beginning to gloss over from reading it. Counter-Strike: Global Offensive, however, is making a big deal about its intention to provide unparalleled control in sound by opening up more audio tweaking options than the standard, "How loud is the yelling compared to the shooting and the music?" They've even provided colorful charts and graphs to explain what this means.
You may be looking at that and still be asking, "But what does it mean?" The devs explain in their blog post that previous CS titles used a single surround sound preset, optimized for 5.1 speakers, and mixed it down to fit less snazzy audio set-ups. CS:GO, on the other hand, will have optimized presets for everything from stereo headphones all the way up to those big surround speaker rigs. Plus, you'll get settings to tweak things like virtual speaker placement (if you wanted to, say, have your "left" channel sound closer to true left instead of the default front-left.)
CS:GO is currently pre-purchasable on Steam for $13.49 on Steam. This post details the pre-order plans and the huge patch going live on the 14th.