Speaking as a Swedish software developer, I don't know any local professional in the field who would even consider writing identifiers and comments in anything other than English. Documentation is a different issue where the choice depends upon the target audience: if it has a chance of being international, it's always in English.
I think the reason can be summed up in four points:
culture - IT is done in English, that's just how it is.
literature - Who would translate The Pragmatic Programmer to Swedish?
communication - It's the lingua franca of software engineering in international settings.
harmonization - All APIs are in English, so having Swedish identifiers would just look stupid and not read very well.