If you're just gaming, get the i5-2500K instead of the i7-2600K. The i5 rocks the i7-900s when it comes to games, and OCs like none other. That will also give you another $100 to spend on other components (ideally invested in the GPU).
To me, the Lanboy is somewhat of a gimmick. You can get as good or better airflow in a standard case, because airflow is about direction, not just the amount of air in the case. Get a solid case like the Cooler Master 912 or 922; they are mid towers but are very large, and cost at least $70 less.
I would get an Asus P67 board or the ASRock Extreme4 P67 (only ~$150). Their quality is a bit better than MSI's, and the ASRock is great for overclocking.
Your RAM is *ok* at best; look for a set with a Cas Latency of ~7 and speeds of 1333 or 1600 MHz. The Latency is more important.
Forget the WD Black; SATA III is now limited by the drives, and no platter-based drive can take advantage of the increased bandwidth yet. Get a Samsung F3 1TB; it's cheaper and is the fastest hard drive out there.
You could also afford to put in a 64GB SSD for your OS, which would drastically quicken your boot times. They only run about $120 now, and since the next generation is coming out, they're going on sale here and there.
I would suggest a GTX 560 at the very minimum. They overclock very well, and are faster than the GTX 470s at stock settings. You may even be able to afford 2 or get a better GPU like the 580.
The power supply is dependent primarily on the GPU, but I would suggest something in the 750W range. Corsair makes some of the best PSUs out there, but Antec makes some good ones along with XFX (specifically the Black Editions).
If you could afford anything, I would say a GTX-580.
But money is always an issue, so paying for that could get sticky.
I agree with Boiler that you have several components taking up money that could be recovered to offset the price of the GPU.
First thing you need to decide is whether you're going to build this system to always be a single GPU, or if you want to allow for crossfire/SLI later. You said no to that, but your case and power supply selections imply that you're preparing for SLI.
Speaking in general terms, I would think that between the CPU, Case, PSU, and hard drive you could take back almost $200 from that build without impacting performance at all... in fact it would probably be more quiet as well.
Having that $200 would come in very handy when you're trying to get the best GPU you can afford.
What are the features you're looking for in the case specifically? Like would you need to carry it around to LAN parties and whatnot, or does it just have to sit there, look good, and keep components clean and cool?
There isn't much of a selection on the motherboards atm. The one you have selected is good, but I imagine in the next couple of weeks there will be more (and maybe cheaper) alternatives. Each manufacturer has probably 8 motherboards for these CPU's, but so far we've only seen a couple from each.
Have you definitely ruled out using two video cards, or do you want to keep that as an option? That would have an impact on selection of cases and power supplies.