Take a look at the newest update to the ever mixed-bag of mayhem, dpreview.com, and see their latest article comparing the D800 to the D800e.
They make a strong case with visible evidence that the D800e does indeed offer a resolution advantage in context to the content you shoot, and the file format chosen to shoot in. JPEGs out of the D800e are noticeably better. The detail of the link fence is mushy on the D800, but resolved articulately on the D800e, and even with sharpening applied, the D800's mushiness can indeed re-approach D800e level lusciousness, but not quite match the detail difference that a D800e provides.
The other context that comparison requires is how big will you print?
If you print 24 x 36 and much larger, then the D800e has the win I think, assuming you shoot subject matter that includes the fine detail that the D800e can capture with really good glass.
Even without the D800e's advantages, the D800 is still a top-tier competitor killer, and most importantly, a phenomenal tool whose limits don't limit creativity for large print making like say a noisy low megapixel camera would. Either is awesome.
I'm going D800e for landscapes and the like, but if I was a portrait shooter I'd buy the D800.
Hope this is a help,
Locophoto