For such a big game on such an unpredictable platform as the home computer, Starcraft 2's launch seems to have gone rather smoothly! That doesn't mean it's been perfect, though.
A number of niggling bugs and issues have popped up over the course of the past 24 hours, some of them with fixes, some of them simply listed so you know Blizzard knows about them.
The more notable ones include issues with Nvidia drivers for Mac 10.6 owners, general Battle.net connectivity issues (I've had trouble logging on all day), and best of all, graphics cards overheating on low-detail screens, because "the game has nothing to do so it is primarily just working on drawing the screen very quickly".
Aside from the Battle.net issues (which will only really affect those looking for some multiplayer action), most are relatively minor or isolated events, and shouldn't be too big a deal for most users out there. Just in case you are affected, though, you can check out the issues in full detail at the links below.