Thanks! I'm generally reserved until I get to know people as well. It's been my experience that most americans really don't fall into that loud/obnoxious/rude/belligerent stereotype that seems to be making the rounds (maybe not this generation's teenagers, though...).
Really, the thing that scares me the most about moving somewhere like sweden is learning the langage ;) I don't really have a gift for (human) languages, and swedish seems pretty tough already.