1| This card and block feature being released now is a little too late.
2| This would've been best explored on a GTX 780 HOF edition in the first place
3| Even if they are planning to launch the waterblock, imminently, I believe they are yet testing it out for implementation in their future HOF lineup of cards(much like Asus' Twin GTX 560Ti on one PCB idea) since they were in the works to do much more on their HOF series.
4| If this is eventually released I hope that "that" piece of brushed aluminium isn't making contact with the waterloop/liquid as that should lead to a horrible galvanic corrosion story.
Anyways this is a good move so far. No need to bug EK over their thinkcell page to get waterblocks - if this materializes.