So would u have to cool it constantly? or.. wat?

If they stopped cooling it the processor would die.

Now, with that big of a heatsink how do you plan to close the tower? How do you plan to renew the liquid nitrogen without blowing up your PC

you will notice that this was done outside... so not very safe I bet. Also you would never be able to keep switching the system on and off as the ice would damage the pc

I couldn't help but think that there was a lot more they could have done to insulate the rest of the system from the CPU's immediate area .... I'm sure this system must have gone onto a crashing spree once all that ice built up and started short-circuiting all those electronics around the CPU's base .... for one example, they could have gone as far as to coating that area with silicone, i would think; or in the vary least, covering that area more to protect from the super cooled 'steam' flowing over the top of the copper tube and down onto the motherboard.

Secondly, the over-use of thermal pastes ... from my understanding, application of thermal paste between a chip and a heatsink is supposed to be EXTREMELY THIN and evenly spread; any excess paste REDUCES thermal performance and just splotching it on can easily introduce air bubbles which would cause 'hot-spots' wherever a bubble lies.

If your going to draw attention to yourself by breaking some world records, it would be probably a good idea to do everything you can to make everything as perfect as can be ... for example, cleaning up the copper soldiering residues to 'good enough' levels isn't Good Enough!, go all the way and use scouring pads, polish and some attention to detail and people will respect you the more for your efforts and clean presentation. A key to success in life = Strive for excellence in whatever you do! Don't settle for second-best.