"The main point of these fake movie UIs is different than that of real UIs: to tell a story very quickly, not to reveal and enable function."
This sentence is quite telling and ultimately the main reason behind the flash of (or lack of flash) in comupter UI's in motion pictures. They are used to drive the plot. Everyone here has surely noticed the cool looking way people "hack" computers in the movies. How about the slowing ticking progress bar and flashing data presented when people are illegally downloading files to a usb drive. In some movies the UI is so 3d and gesture advance as to make the user "dance" to interact with it. This is to present the virtuosity of the user at his craft. In other movies retro monochrome looking console UI's are used to give things an analog grittiness. I find the whole thing quite fascinating. Its a dream job if there ever was one.
The coolness of fictional media UI's does make it hard to design regular UI's for real products. The user expectation is pretty high. I always chuckle a little when I start up my PS3. The main nav is just a menu tree. The eye candy floating in the back has no function use whatsoever but most of the processing during the navigation phase is consumed by presenting the cool liquid effect in the background.
I've been watching "The 1st 48" (US reality show about solving murder cases) for a while. I love how all of the UIs are basically just MS Windows and maybe a web based perp search application because is what cops actually use. I compare this show to CSI all the time and "CSI fan" friends hate me for it.