Someone at 2K Games really dropped the ball with this one... While it has been common for Russian Steam users to see games with specific Russian versions - at a cheaper price point and as region locked to Russia - 2K Games just informed gamers in Russia, CIS and Baltic States that no, their Borderlands 2 preorders didn't transmute into "Borderlands 2 RU" by accident. As a side-effect, Borderlands 2 Season Pass they may have purchased isn't going to work with the game. Sure, they are offering an apology due to incorrect information during preorder period and are offering refunds when requested, but the problem remains.
So if you happen to live in one specific corner of the European Union, namely in the states of Estonia, Lithuania or Latvia, you are being offered Borderlands 2 on Steam, at full EU price point, more than twice the price of the same game in Russia - yet what you get is the Russian language only-edition of the game that cannot be played in multiplayer with the rest of the world. Russian isn't even the official language in any of these countries. They are independent states and members of the EU!
That, in my books, is just plain unacceptable and we've inquired 2K games for their justifications. At the moment, the unofficial workaround is to cancel your preorder from Steam and buying the game from Green Man Gaming (they haven't heard of Estonia either but it'll work if you just put "UK" as your country instead). That way you will get proper global version product key which you can then activate on Steam. Now if you happen to live in Russia, even this method is blocked (GMG won't sell you the game) unless you resort to VPN tricks and appear to the online store to come from non-Russian IP.
On a more general level this is just terrible way of handling things. I can understand fully that for the Russian market, it makes sense to offer RU-only versions (at a lower price point, to match the general cost of living in Russia) as an option. But to forcibly block the sales of "full price" global version of the game to some regions is a very bad idea. This combined with the silly release date dance between US and EU (EU getting many games several days late) is causing me to wonder if a VPN account with endpoints around the globe is rapidly becoming a requirement for PC gaming?
There are threads on the issue at Gearbox Forums and Reddit.
Update, 20th September: 2K Games has listened to the complaints and taken steps to resolve the issue, details here.