You have to love Steam for the access that it provides to the whole global community. Half the fun for a typical small studio is watching the game's revenue climb up, the other half is watching new countries appear in the Regional Sales update.
As of right now, there's a very close tie for top regional sales between USA, UK and Germany. USA leading by a single unit (!).
New countries that recently showed up in the sales report: Turkey (beating Sweden), Brazil (beating Finland), Ukraine (beating Switzerland).
Aside from English, German and French and Russian localisations seem to have been the right choices: strong sales in all three regions. Also, Brazilian Portuguese, and Italian. As to Polish, Czech and Spanish, I guess we need to wait for word of mouth to get through to those regions, for local players to show up.
We'll keep you posted, if you're interested in this sort of trivia?