Yup, they dropped Thunderbolt on the new models. Both of the Haswell systems are the same except the processor (i3 or i7). I'd be interested to see if Gigabyte does a BRIX that has a rear analog audio port, though.
Yeah, it's the same idea as a car - it's cheaper if you buy it as a package, because individual parts are going to be way more expensive if bought separately. Especially on stuff that is sold in low volume outside of the mainstream product, like a laptop CPU. A quick Newegg search is showing me an i3 Haswell laptop for $449, even though the CPU tray price is $287 and Windows 8 is $99, which would make the laptop itself $63 (screen, motherboard, shell, keyboard, touchpad, RAM, battery, A/C plug, etc.):
http://www.newegg.com/Product/Produc...82E16834314150
http://ark.intel.com/products/75459/Intel-Core-i5-4200U-Processor-3M-Cache-up-to-2_60-GHz
http://www.newegg.com/Product/Produc...82E16832416550
Probably my only real complaint with the NUC is the price, but what you spend up front nets you a good i-series mobile CPU, a tiny low-heat, low-noise computer, and super low wattage. The new Haswell NUC is like 5 watts idle and 30 watts load...so even at max, it's only half the power of a 60-watt light bulb, which is pretty crazy.
I think the new ones will definitely be a hit with HTPC enthusiasts. The inclusion of an IR port is really nice because getting a good-quality living-room/family-friendly remote control for a computer is always a hard thing to come by.