There are many reasons why running in NOLA is a great experience.  Here are my top 5 reasons:

1.  If you don't like hills, New Orleans is your heaven.  There are no hills.  None.  Monkey Hill (at Audubon Zoo) is the highest point of the city.  (Then again, if you're planning on racing the SF Marathon you're screwed.)
It's a mountain!
2.  You can experience the running of the bulls without having to go to Spain - or risking your life.
That's gonna leave a mark!
3.  It's a great way to burn off the 50 Beignets you ate at Cafe du Monde.
That's my kind of carb loading.
4.  If you run in a red dress (or less!) no one looks at you funny.
Ok... so maybe there's not a lot of running.
5.  People hand out beer and martinis during major New Orleans races.  (Did I mention costumes are cool any time of the year?)
Mardi Gras Marathon 2009
"Water" Station around Mile 8