My wildly unrealistic wish list
I'd like to see a gargantuan machine that you would essentially carry around in an art portfolio type of case.
1) 20" display from curent lineup
2) dual G5 CPUs--one available while on battery power, dual config if plugged in to AC.
3) dual expansion bays (a la my beloved Pismo, except MUCH BIGGER) so that you could slap in dual batteries for 10+ hours of portable work, additional hot-swappable hard drives for big design/audio/DV projects using AC power, superdrive, or anything else they'll invent over the next 5 years or so (MCE can take anything and make it work in an expansion bay)
4) HUGE touchpad area that doubles as a graphics tablet for art and design applications, as well as for business purposes ("So, we've reached an agreement on your widget order sir? Well then sign right here on the trackpad and I'll transmit your order instantly.")
5) an indestructable housing. Scratch resistant with perhaps cleverly integrated rubber bumpers on the corners and edges to prevent damage from the occasional real-world jostling a laptop faces.
6) perhaps dual CardBus slots--one for standard expansion, the other dedicated for communications--a cell phone uplink to the office a la Blackberry
7) usage of mylar film speaker technologies like
Martin Logan speakers do. With a footprint this big, the speakers could be 3" x"9 each, and using the mylar film flat speaker technology they would sound huge and hifi compared to any other portable unit.
No, this wouldn't fit comfortably in a big purse like a 12" does. This would be a complete desktop replacement and a small boardroom presentation platform in a portable form factor.