http://www.gamespot.com/articles/ste.../1100-6448088/
Basically Steam has to collect tax for other countries now, so looks like they're just going to raise prices by that much to compensate. Which normally I'd think is fine, except since a while back when the physical distributors got all stroppy, Steam artificially raised prices in many of its markets to be more in line with regional physical copies. So the price Steam sells a game for in USA is probably about 3/4 of what it sells the same game for in NZ/Aus etc.
Which is why I usually just buy the steam code from Green man games and add it to my Steam library that way. Which btw will presumably still work as then Steam won't be the entity selling the goods, so the tax codes probably don't even get involved.
In short, fuck you Steam, and everyone in general that does regional pricing of digital goods.