The new generation of high-quality, video-enabled DSLRs is thoroughly changing both the high-end still camera and camcorder markets. It's now inconceivable for a manufacturer to release a $1,000+ DSLR without some sort of HD video capability. Even Sony, the lone holdout, is rumored to be biting the bullet on November 18 with a HD-capable DSLR that will compete with the Panasonic GH1. (Technically, the GH1 isn't a DSLR, it's a Micro Four Thirds camera without a viewfinder, but it does everything that a DSLR does.)
The ironic thing is that RED, the company that made cinematic video production much more affordable with the RED One, first identified the need for print photojournalists to be able to shoot competent video without having to carry two cameras. It rechanneled its development effort for the Scarlet, which was originally supposed to be an inexpensive, handheld 2K camcorder, into a video-capable DSLR. That was almost two years ago, and not only has RED not yet shipped the Scarlet, it hasn't even provided a definitive list of features or release date.
When the Scarlet comes to market, it will have to compete with a variety of products from virtually every major DSLR manufacturer, at price points starting around $1,000 to over $5,000, with a huge range of capabilities. While Nikon, Canon, Panasonic, etc. weren't educated about the market opportunity solely by RED, it didn't do RED any good to tell its competitors so early about what it was doing. In my opinion, the early announcement was sheer hubris: "We beat you with the RED One, and we'll beat you again with the Scarlet."
Once you make a product announcement, you have to get the product to market quickly. You cannot assume that your competitors are too slow or too dimwitted to respond. The first time around, competitors took RED for granted because they were a new company, run by someone from outside the broadcast electronics business. Lots of companies like that had announced products, perhaps even shipped a few, and then sank beneath the waves. But RED was for real, and its competitors learned to pay attention.
If you're a new entrant into a market, you usually get one free pass where your competitors underestimate or dismiss you. Once you become successful, you're on their radar, and the requirement to get to market quickly becomes paramount.