Yep, the language will be Swedish because Notch is.

There's a language changer in the top right hand corner of the page, here's a little picture which shows you:

http://imgur.com/a5Mxj.png *Converted to link, the picture width is too long. ^^;

And yes, Fish is right, the money is automatically converted into euros.
When you proceed past the initial buying page, it will show you how much it will cost in your currency, but it needs your card details or account first to be able to give you the converted amount.

Hope this helps!

~Scoopade