Or let EVGA launch it as part of their watercooled classified range, that will be 1 - 0 to NVidia with AMD having nowhere to go.
What is with the bashing the 295x2, the AIO limits it, it can't overclock, it doesn't save power over two cards. The only problem with that is, Nvidia went air cooling only and ended up with a significantly slower card, the AIO doesn't limit it. You can stick a waterblock on anything but the AIO categorically allows a tdp/clock/dual gpu card that can't be achieved with a stock air cooled card.
Multiple reviews show it can overclock, there is decent headroom in the cooler(you linked to a site showing it running 646W in furmark, leaving almost 30% cooling headroom for stock, and gaming it was only running 430W, leaving an almost 50% increase in cooling capacity. 430W is also significantly less than double the 258W single card power usage.
If Nvidia release a waterblock only card, firstly, price increases, secondly it literally can't run out of the box AND you suddenly get 95% of review sites unable to review it. It goes from something that a few hundred thousand people might consider with an air or AIO cooler, to something only a couple thousand people would consider buying.
Even with a waterblock it looks set to be slower and twice as expensive as the 295x2, regardless of what Nvidia do it's a win for AMD.
As for the cooler, the cooler hasn't changed in the pictures, identical cooler but it's got an extended pci bracket. With a wider bracket they are making it difficult(not impossible, can always remove it) to put two cards side by side, there would have to be at least a one slot gap.
While increased airflow could be a sign they will release it with higher clocks than intended, it could also be as simple as even at the listed clocks two cards in sli without a gap isn't actually safe for the cards. I lean towards the former but the latter is possible.
They've designed a card with a target for TDP and cooling, with the same heatsink and power circuits it's hard to actually increase clocks significantly or increase cooling. I'd be very surprised if they can delay a few weeks and then launch it with 20-30% higher clocks. We'll see.