Ryan, there are some other downsides other than the slow continuous shooting speeds, which I'm not so sure that some may understand.
Based on the D3X I would expect that the D800 will make high demands of lenses. For those D700 users, jumping up to the a D800 with "pro" glass, they'll be alright, but for those D700 users with considerable "consumer" glass, I don't think they will find those lenses work so well on the D800.
Moreover, based on the past experience of others who moved to DSLRs with major jumps in MPs/sensor, I suspect that there will be many unhappy D800 users at first, users who don't use solid hand-holding techniques. The D800 will require that sloppy technique be replaced by high quality technique. This will be true of tripod use too, with long lenses on this camera.
Neither of these downsides are knocks against the D800 itself. I think the D800 will prove itself to be a marvelous camera, based on the specs. I think D800 users will learn better technique, and will replace their glass, but at first we may be hearing similar complaints of unrealistic expectations.
We saw this happen when Nikon moved from the D70/D70s to the D200, and I suspect, we'll see it again. Then, after a while, the complaints and problems will be replaced with high praise, just like in the past.