But it does not solve a need, from what I can tell, that Kayak or other meta-searches solve. And at first glance, it seems slower than Kayak and has fewer options.
Visually, I think some people would debate whether your layout is more useful than the clutter of Kayak/Priceline/etc. It certainly meets the guidelines of attractive typography and whitespace but it took me some time to interpret what's going on.
In one real sense, I think the width of your site is a real problem. There's a reason why content sites, like blogs, usually fix their content width to 600-700 pixels: because it's hard to go from left to right and back to left across a wide width. Your current layout forces this upon the user in a way that's not very easy to read. Most people might say that Kayak is ugly and cluttered but it is much much easier to figure at a glance. Sometimes, ugly/cluttered is better...kind of like the debate between HackerNews and DesignerNews.
I'm sounding too harsh here...but only to be helpful. This was a site I showed all my coworkers because I thought it was pretty cool. But "cool" or different isn't enough in the travel space, unfortunately.