Is the FX revolution fizzling?

I am a little surprised by Thom's views on DX - at least I don't share them. Personally, I don't see DX as offering anything over other formats. It isn't particularly small, or any more convenient, and doesn't offer significant IQ benefits over some formats like MFT. The OM-D E-M5 has a more capable sensor than any APS-C Canon, and the Nikon DX are only marginally better. In terms of lens support, even Zeiss have stated that they will be launching a line of lenses for MFT so the future for MFT looks good.

DX may be a volume seller, but it's a bad product for the companies that make them due to the small margins and low volume of accessory sales that it drives. I see an awful lot of new APS-C Canons, all with the kit lens mounted on them - how many buy another lens or ever change the lens even? I think many FX bodies on the other hand generate several times their price in higher margin lens sales during the lifetime of the body. Managing to sell a single premium 1.4G prime, or a 24-70 2.8G, or either of the 70-200s, or a pro UWA, or a PC-E during the life of a D600 almost doubles your sales - maybe not this Christmas but maybe next.

As for a pro DX replacement - I am in Asia and the de facto top of the DX line here is the D7000. I don't think the D300/s has been available here for some time - if it's for sale chances are that it's on display in some store, or in a price list and it's not.

FX on the other hand has seen a tremendous increase in number of bodies available, and in interest and demand. Supply of lenses has also increased dramatically with new premium FX oriented lenses from Tamron (24-70 2.8 & 70-200 2.8), Sigma (including the new 35 1.4), Zeiss (the 25/2, 15/2.8, and the 135/2 - due around now, as well as an entirely new line next year), and even Samyang. Everyone seems to be falling over themselves rushing to bring out new FX lenses.

If the D800/E goes away, it will be replaced by something better. So far, the D800/E is the only camera that the entire new super high spec Zeiss line (starting with the 55/1.4) is designed for. I'll wager that the lenses in the new Zeiss line, as well as the 135/2 will have demand hugely outstripping supply. The high end FX line is healthier than ever.

Maybe (hopefully) we'll see mirrorless full frame cameras from both Nikon and Canon which can use existing lenses through an adapter (sort of like the EOS M).

For DX, it looks pretty clear that the manufacturers of both cameras and lenses would much rather people buy a full frame camera.