F1ach: Eventually stopped dicking around and progressed the story a wee bit, "Find a Boat".
Initially I was a bit annoyed with the boats until I discovered that using "A" is pretty awesome :)
Just cruising around the swamp, there seems to be a fair few "dungeons" for want of a better word, where you can dock your boat and go in to explore and kill stuff, got a nice Venom Mod in a cave there, also found the Santa Maria (name?) Mission, I think that was used in a gameplay trailer for the hub defence, it looked like a likely spot for it anyway.
I think the game seems a bit more difficult than the last one, also I'm at Lv 29, theres not really any more skills I'm too bothered with (Wunderwaffe when i get access to guns is all) and I still havent left the first area and have maybe 3 skill points banked for use on Wunderwaffe.
Yup the Mission is eventually a hub with a defense sequence. It was great fun and got a little crazy. The addition of the dead zone dungeons is awesome for the people that like to explore. I just got to Henderson last night and one of the first dead zones I came across was awesome fun, a whole basement just packed with zombies and some bosses thrown in, and a ton of rare parts and chests to make it worth the effort. It does seem a little more difficult, some of the new bosses are nuts, drowners hit crazy hard if you give them the chance, and old school bosses like thugs take a more massive beating than in the first game.