It isn't something new, that east european (meaning Europe east of the easternmost EU member states) and eastern Steam-keys are region locked, due to the fact that they are much cheaper over there. Poland, Slovakia and the Czech Republic are EU member states, so activating and playing the game without further actions (e.g. IP tunneling) shouldn't be a problem (in fact it should be against EU law if it would be a problem).
... and finally an unboxing video:
http://www.youtube.com/watch?v=1i2CPjNWVxI