I think the intoxicating part (at least for me) is the potential of completely changing the composition of a shot. All of a sudden you've got the ability to remove fully 50% of the image, and still have a great photograph. More than once I've wished I could change a portrait shot into landscape once I've been looking at it in post. I've never really thought that a crop sensor did much to improve "reach" of a lens considering the trade offs, but I would think a lot of you BIF types would get something out of this.
Since I really can't justify this for my "business end" of photography, I'm content to wait and watch (dirty rotten lie). But the creative side of me would love to get this thing. We all saw the moiré coming, and a nice neutral gray is perfect to show that off. But it doesn't seem any worse than some of the moiré I've already seen on the plain old 5D mkIII at this point.
Anyway, aside from that - I can't see what good this could possibly do me. Even when I was doing billboards and packaging - I hired people that knew what they were doing! I confess I loved pulling 4x5's hot out of our Colenta processor and putting them on the light table with a loupe to look at the pores on a model's skin, and using the images for layouts. Today I'd be doing the digital equivalent - except I'd be all dressed up with no place to go! Pixel peeping - expensive thrills.
Then again $3700 - $3900, I don't see how I could just get the 5D mkIII unless it's a lot lower in price from its MSRP (and it's getting there), or we do find some "features" that make these models less palatable than the mouthwatering visage these cameras present at the moment.
BTW, I do see a hint of moiré on another building just to the left as well...