EDIT: I suppose I should expand. In the past I have built a gaming rig, used it for four years, given it to my wife who uses it for four years, then it gets retired. This needs to fill a similar role. I don't plan on upgrading / expansion down the line, hence using up all the slots. This will be my first time working with Mini ITX. I am somewhat nervous about fitting that graphics card inside the case, but the product dimensions check out.
Mini-ITX is so interesting . Im tempted to build one one day
You have done well but you do have one mistake in your build . RAM must be 1.5 volt [ or less] or it can potentially damage sandy bridge processors .
Your power supply will work but a 600+ watt unit would be operating under less stress .
I really like your build. Next time around, I will do the same.
1) As to ram, 1.5v is the norm, but 1.65 is the limit before you do permanent damage to your cpu.
It really is a moot point because the sandy bridge ram controllers are so good that there is minimal difference in real app performance or fps between 1600 ram and anything faster.
2) Will you use an aftermarket cooler? The stock Intel cooler is ok up to a point, but it gets noisy when it spins up under load. You will need a low profile cooler since the psu gets in the way of a tower type. SPCR used a Scythe Samurai ZZ coolerin their review: http://www.silentpcreview.com/lianli-pcq08
I love the red color, I used it in a V351 build.
3) I would agree with outlander-04 that a touch stronger psu would be a bit better. Look to Seasonic, XFX, Corsair, PC P&C, and Antec for quality units.
This time of year, you can get some good deals. A silver or gold rated efficient unit will be quieter. Also, I see your pic was modular. That is ok, but you will be using most of the leads anyway. I see modular as a plus, but not a requirement.