This was a no brainer, but some people were concerned that AMD would lock the specification and wouldn’t allow any changes, just as Nvidia did with the Titan. Well it won't happen as apparently AMD knows that value of slightly higher clocked cards with elaborate cooling and that some people want to go after them. There is no doubt that the Radeon R290X will be one hot cookie, but a slight clock increase will likely give a few percent of added performance, just enough to make the sales pitch a bit easier.
We would not be surprised to see dual or even triple fan designs, but at this time, we don’t hear that anyone is working on the water cooled edition of the card. AMD will of course not allow this at day one, it will want to send vanilla cards at first and then the second batch of this new big chip 290X cards will come with custom coolers and custom clocks. Let's not forget about the plain R290, as it could be a very attractive product with a non-reference cooler and a factory overclock, since it should end up significantly cheaper than the 290X.
AMD will try to make as much money on bundles and after the first wave it will release the custom version. Nvidia still waits for AMD to lock down the launch date and price as well as to see the final benchmarks before it makes its move and potentially adjusts prices or releases a new version of Titan.
The game is on, AMD got Nvidia’s attention, and the attention of many gamers. It took AMD years to get so much attention in the high-end PC GPU market, but now they finally got it right.