I found the prospect of a post-Katrina urban fantasy/paranormal story with a twist of romance to be a pretty solid premise. Sadly, I just couldn't connect with the characters and when that connection isn't there, it's a challenge for me to get on board with the story.
The most interesting bits were the descriptions of the post-Katrina New Orleans and life in the city immediately following the disaster. I would argue that Katrina was a fairly vivid character in the book [and the only interesting character, at that]. The newspaper headlines updating you on the progress of Katrina recovery at the start of some chapters were a great addition to the story. I wanted to like the world building - Green, Red, Blue wizards...historical figures crossing over from the Beyond back into the world...etc. But, at the end of the day, I just couldn't get immersed in the story.
I think the book/world building/premise has great potential and other people may find the book very interesting. I think the biggest element that will determine whether you like the book or not is - do you like DJ, Alex and Jake? If you do, then I think you will probably enjoy the book. If you don't like them...well, then I dunno.