Hej and welcome to the forum.
As mentioned before, Google restricts their O/S to various regions such as America, Middle/Far East and Europe and as part of that agreement, Sony have to follow these guidelines and ensure the product meets this standard. What this is going to mean is that in theory, your firmware cannot be overwritten by a European version as it will be seen as a different region based model.
The real test would be if you have 3.1 and upgrade to 3.2 in Sweden. If it works, I don't think the above statement would be 100% accurate however since the update is just an update, it will not overwrite the core functionality such as keyboard/western language support.
It is something I wish was more known or made publically aware but as with everything, the whole limitation is difficult to print or be known prior to sale.
Hope that helps.
