Saw a post by Crono_marle on the Shoryuken.com message boards that you can preorder Street Fighter 4 on GameStop.com. Right now it's only listed for the XBox 360 and PS3 at $59.99; unfortunately there's no PC version.

The preorder is currently set to ship on 2/3/2009. You should take this with a grain of salt though, because the dates listed on early orders are sometimes way off.