Guess we'll see what happens when it's actually released with specs and benchmarks. I'll be purchasing one for sure. Most of the working copies of images that I've got can live on a USB3 or Thunderbolt drive with a separate Thunderbolt RAID to hold my postgres database. Going to put in for two 27" displays and plan on getting one of them.
I will say that I'm not excited about having that huge mess of wires around my lab, but my lab is already that way due to all the stuff I've got plugged in already.
And like I said...the ability to take everything local and toss this little thing into a duffel bag to take home for the weekend or an all night session beats the living shit out of lugging home a 9 pound laptop plus all the other crap just to have an underpowered machine.
My current Mac Pro falls into that weird gap where you can't upgrade it beyond Snow Leopard. I'm hoping that it falls from my employer as surplus soon. The combination of that hardware and Snow Leopard (which is still getting updates) makes it the most stable machine I've ever used on any platform.