Well, Slovenia isn't a Baltic country and Latvia may want to be one, but the Nordic countries see that differently, despite generally fair to good relations.
The Baltic countries are much more integrated into mainstream Europe as a whole than the Nordic countries, which opt out in many ways.
Norway isn't a member of the EU - the Baltics are.
Denmark and Sweden aren't members of NATO - the Baltics are.
Denmark isn't a member of the EU defense council - the Baltics are.
Sweden and Denmark aren't members of the Eurozone - the Baltics are. (Lithunia isn't yet, but is pegged to the Euro and will make full switch to the Euro in 2015.)