Just got the camera and read/perused the entire manual.
It states that you can use a blower but not to actually touch/clean the sensor; send it to a service center instead. (page 397)
Coming from a Leica M9 which I have cleaned the sensor several times; initially with some trepidation but it is quite easy to do.
Do people really send in their cameras just to have the sensor cleaned or is this just Nikon trying to minimize liability? Is the Nikon D800 sensor that much more fragile?
I use the Visible Dust line of products and it does the job just fine.