If as you mention in your other post, you're plannning on 3d work, the first thing I'd recomend is an Nvidia card, the CUDA cores are handy if you want to use mental ray as you can use the iray hardware renderer, you can also use PhysX acceleration in animation simulation in max, which can on occasion came in handy, I have nothing against the ATI cards, in fact Eyefinity is excellent, but I like the options Nvidia offer. Also Nvidia for hardware acceleration in adobe products.
For rendering you'll want as many cores as possible, and you definatly want hyperthreading, when I moved from a QX6700 to an i7 920 the speed increase through hypertreading was jaw dropping, both 4 core chips both at 2.66 stock the i7 was between 2-3 times faster, partly down to the chip architecture but mostly because 3d Rendering is perfect for hyper threading.
If you can afford it I'd say go Sandybridge-E, I get the feeling the first batch of Ivybridge chips will be nice low power quadcores, great for gaming and good clockers, but short on cores. Now Ivybridge-E, that could be interesting.
SSD/HDD look good, I go through a lot of HDD space, but with prices as they are I would just get what you need for now.
That case is a beauty, I'm thinking of replacing an old P180 with that.
Cooling, I've had a Noctua for a while on my i7 920, and it's nice and quiet but I have to say I've been dissapointed by its cooling, it's probably the case letting it down (Old P180 with no cable management) so I've been using closed loop water cooling on a couple of workstations and been impressed with it, I work in a small dusty room with lots of computers in it (6 desktops right now) and aircoolers tend to get clogged so it could be just me.
I don't worry much about soundcards these days, I run a pc through an old dennon amp with a pair of Beyerdynamics and it works fine for me with an old soundblaster audigy, most machines I use onboard sound so that card I'm sure will sound lovely.
Arctic 5? I think there are better pastes these days, some one will know.
I also don't really use optical drives any more, so if you need blue ray, I'm sure that's a great one, it'll install windows really well
Hope that helps.