Workstations at offices, gaming machines, animation and image manipulation will all probably stay on desktops and that will keep them around for years.

The scale of a desktop fits and works. Like how we could make a TV the size of a watch, but we don't because the large 60 inch plazma format, while immobile, has benefits worth the tradeoff.

Full featured mouse / keyboard, larger screens, surround sound are all perks of stationary desktops (I guess you could attach all these peripherals to a laptop, but then you are partially defeating the point of being mobile.