There are definitely swamps in Skyrim (the province, not necessarily the game). Potema attacked Magnus through the swamps in Book 7 of the Wolf Queen.
http://www.uesp.net/wiki/Oblivion:The_Wolf_Queen,_v_7
Swamps will be in game. They're http://i56.tinypic.com/wmce1l.jpg and I'm fairly sure someone has already mentioned them as one of the various enviroments. :happy:
Also Swamp Area I guess that makes the Argonian Fans happy and I like it too. Hopefully the different areas and cities will adapt to the climate like you might see different housing designs if the area is too cold or wet, etc.
Oh yeah, they were mentioned in the interview...