This is typical Apple... trying to drive a new standard well before it's time, combined with a proprietary connector... what a mess! What was wrong with the mini-DVI connector they introduced on the first MacBook Air? At least with the supplied adaptor you could connect it to anything under the sun. Now you've got a killer display that can only connect to a handful of devices that are within a few feet of it... laughable.
Also, do you think ATI or Nvidia want's to develop a card that supports this connector standard just for the niche market that is Mac Pro users (what is that 0.1% of the computer market)? If I were ATI or Nvidia, I'd say "show me the money" and in-turn, Apple's going to force that cost onto us.