Traditionally w has been considered equivalent to v when sorting Swedish text strings (like Umlaut vowels in German). Since a couple of years this sort rule has changed. Now w is considered a full-blown letter, sorted right after v, like in English.
Ubuntu 13.10 with LANG=sv_SE.UTF-8 sorts according to the old rule. Where can I report this old-fashioned behaviour? It should be changed.
I guess this is a very unusual type of change. The rule changed with the 13th edition of *Svenska Akademiens ordlista* (SAOL), published 2006. See e.g. http://sv.wikipedia.org/wiki/Svenska_Akademiens_ordlista_%C3%B6ver_svenska_spr%C3%A5ket