It happens with every new camera introduction: people get their hands on the new camera and they start grumbling about "issues."
The interesting thing is that all of Nikon's warnings about lenses and camera handling on the D800 seem to have done their job: I've seen very few "it isn't sharp" grumbles so far. Fewer than on almost any previous Nikon DSLR resolution bump. Perhaps Nikon will learn from this that much of their problem has been lack of expectation setting in their marketing messages.
That leaves the "other" grumbles:
- Build quality complaints. Not a lot of these yet. A battery door that fell off because a pin was missing (this, by the way, is why cutting off parts to only authorized repair centers was a mistake--it'll take longer and cost more to fix). A miscentered viewfinder or two. Complaints about the plastic quality of the mode selector. But the big winner in this category is the LCD: I've seen a lot of miscalibration complaints, with color tints and brightness issues being the common ones. The camera has some ability to change brightness (and hue in Live View), but the Auto setting appears to be the culprit most of the time.
- Functional complaints. I haven't been able to test this one yet, but there's a prominent complaint about wireless flash reliability using camera's flash as master. There are definitely issues with tethered capture, and I've already pointed out the missing functions in Camera Control Pro. Noisy long exposures once you jump above the analog gain limit (ISO 1600 or higher). The return of amp noise (visible at bottom of frame at high ISO, visible as horizontal bands at long exposures). "No crop" movie is actually a 1.1x crop horizontally (91% of the horizontal width of the sensor).
- Design issues. Why no WT-5 support? Why no RCA video out? Why do the PC-E lenses hit the flash housing in some orientations? Why no camera-wide "setting" ability (still only shooting and custom settings banks)? Why do we still have the 1EV bracket limit outside of the built-in HDR?
- Documentation issues. Uncompressed HDMI video out seems impossible if all you do is read the manual, yet it works if you know the secret spell and wave your wand correctly (Relashio! Engorgio!).
Personally, nothing so far seems like anything other than the usual product launch noise level. A few things will need to be addressed by firmware fixes. Quality control will get better with each new wave of shipments. The design issues are typical Nikon, where they seem to have blinders on to things that are obvious to serious users.
All in all, a quiet post-launch, as far as post launches go.