I think it is a given that leading edge digital image capture is already very close to 35mm film. CCDs are slowly giving way to Si based photodetectors (CMOS technology) as demonstrated by Foveon (http://www.foveon.net/) who have a square 16Mpixel device available. You of course pay the price in storage and energy requirements. It will be a while before these devices become available in larger formats but it will happen. It will probably be longer, however, before the storage and power requirements are brought under control with dense magnetic RAM (or some comparable technology) that can replace disc drives and operate on a few AA's.
As for "ressing up smaller digital files", which I assume means some kind of interpolation (?), forget it. You don't get more resolution this way, you just get bigger mushier images.
For LF field photographers, digital is quite far away. Not so far for studio though. Lets just hope the film companies don't quit too early!