Last wedding I shot there were no fewer than 3 D90’s in the hands of guests, it is a consumer level SLR. Nikon does not even consider it and advanced level SLR like the D300.
It is a plastic body with little to no weather sealing and takes SD cards (As any camera shop how many broken SD cards they see a week vs CF) As well if the customer wants video they should hire a videographer, I would hate to be in a video mode and miss a great shot because of it.
I was quite happy to have my D700 and D300 with grips on both, I can shoot all day and not worry about my batteries, and even if they do die, my assistant can change the batteries in the grip while I keep shooting with the in body battery.
From a working perspective I would rather have the stronger bodies than the video feature any day.