Niether for now! Instead, I'm going to let a statistically significant number (...and I have no idea what that may be -- I'm not that smart!) of fellow Nikonians get the two versions and wring them out for me! Then -- if I decide either will do things my D700 will not do -- then maybe I will be urged to choose one. In the meantime, the growing crescendo of people speaking out in favor of the D800 or against it is wildly amusing -- considering I don't think anyone who has one or the other is talking!
Also in the meantime, I'm going to continue to shoot 200 to 1,000 images a week on my two D700s and create the best possible photos I can. The day the D800 was announced, I noticed absolutely no dimunation in output IQ from either. In fact, I just got a splendid 70-200mm f2.8 VRII lens and THAT IS making a difference.