At this moment in time the D700 is the closest thing Nikon has to a direct competitor to the 5D Mark II (speculation about a possible D700X aside). That said, the D700 is a very different beast with a very different design ethos; one that sacrifices high resolution for sensitvity and performance. Putting aside the spec differences let's look at how these two rather ill-matched competitors fare in a pixel level studio comparison.
Canon EOS 5D Mark II vs. Nikon D700
Canon EOS 5D Mark II: Canon EF 85 mm F1.8 lens, Manual exposure,
ISO 100, JPEG Large/Fine, Manual WB, Default Parameters (Standard PS), Self-Timer
Like the comparison with the original 5D, this comparison presents a problem; the 5D Mark II has almost double the pixel count of the D700, making a direct comparison at 100% rather moot. That said, on a per pixel basis, the 5D Mark II is sharper and produces more fine detail, helped by Canon's slightly higher in-camera sharpening. There is no visible noise in either of the cameras at their base ISO settings. If you need a lot of resolution for very large prints there's no doubt at all that the EOS 5D Mark II is several strides ahead of the D700.