Yes, it is impressive. But as insiders we know the real story. It's a beautiful "reimagining" of reality, since the colors are not what one would see but are "assigned" colors for each of the gaseous components. If it helps NASA to sell programs like this, I am all for it, but they should more forthcoming about what the public is really seeing here.
Uhh, what? The link posted very clearly states that
The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.
so no insider info required.
I thought this was a well-known feature of astrophotography. Not only does it result in visually pleasing images, it also serves real science by helping visualize different gases and their concentrations. Human vision is not equipped to deal with the vast variance in wavelengths, so it's much more useful to compress the colorspace to something we can readily see - think compressing your ProPhoto RGB images to sRGB for web use.
And what ckimmerle said. It's not like moderate saturation and color accuracy are in vogue in these days of HDR and overuse of Vibrancy slider.