Here Comes the D800

As a long term Nikon DSLR user having used a D3x for about 3 years, I would lie if I wrote that my photography has been significantly limited by equipment. The D3x remains a brilliant imaging device usable in a wide variety of situations but particularly at ease in landscape work thanks to its rugged design, sharp sensor and above average DR.
Why a D800?
  As a current happy D3x user, why upgrade to a D800? Is there any good reason besides the forgivable desire to own the latest toy in town?
On the function side, the D3x feels a bit dates compared to the D800:

It is heavier and bulkier,
Its live view works as a perfect focusing tool, but feels a bit dated,
Its auto ISO works very well when shooting moving subjects but is not well suited for general photography with zoom lenses,
There is a mechanical link between the mirror and the shutter of the D3x. This means that it is not possible, even in MLU or live view mode, to take 2 images in a row without mirror movement, the D800...