Everything that I've heard says there's a lot of hurry up and wait. Run a half mile, wait at an obstacle, run another mile, wait, etc. Might be an ok thing though because I'll be sucking wind hardcore.
I've done the Rugged Maniac (5K mud obstacle course) here in KC three times and the hurry up and wait thing is by far my biggest gripe. There were 10-15 minute waits at several of the obstacles and it took a lot of the challenge-fun part out of it. The first one was great because very few people knew about it. Popularity is great for the organizers, but it took some of the appeal from the competitors.
As far as training, yes, you'll want to train. Since it's only two weeks away, you're not going to improve much, but any little bit will help. It's going to be in the 80's here this weekend, so just start hydrating now to get yourself ready for that.
The best thing about these runs is the people. I never really encountered anyone that wasn't having a good time. Hopefully you are going with another person or a group. My last time out, my friend got sick the morning of the event and I ran by myself and it takes about 95% of the fun away from it. Like I said, the other runners were cool, but try to stick with someone else, especially if you're not doing it for time.
If this is your first mud run, a few tips. Don't wear anything you might want to ever wear again. I've torn a shirt and snagged my shorts on rocks crawling through some of the obstacles. Bring towels, a bag for your dirty clothes and extra clothes. If you can, bring extra water to wash off once you get back to the car. The showers do a good job taking care of most of it, but you still walk through mud on your trip to the parking lot.
For the course itself, once your shoes get caked with mud, it feels like you're running with 5lb weights on each leg. It's worth it to take an extra second to knock off some of that mud if you have the opportunity.
Let me know how it goes. I've considered doing the Warrior Dash, but haven't done that one yet. I'm curious to hear how the obstacles compare/differ.