That was true up until the CoreDuo line was released, which was right around the time of the switch. I don't think anyone who knew what they were talking about was, at that point, contending that AMD was outpacing Intel.
Anyways, the idea of the UMP was cool about a year or two ago, but lately I've been less interested in the technology. Here's what made me look twice: the Asus eeepc (arguably the best of the UMPs, when you consider form factor, features, and price) vs. the touch/iPhone. The only thing the eeepc has on either handheld is a keyboard, expansion ports, and a bigger screen. The handhelds, tho, have superior battery life, a more innovative input mechanism, and most importantly portability.
I think my point is that rather than a 7" laptop or even a tablet, I'd rather see a 4" touch with an (obviously) larger, higher res screen and BT to connect it to a BT keyboard (and mouse if you wanted). A small, option docking station with some ports including USB, DVI, and audio out would certainly make it really interesting in my book.
Slightly larger/higher res multitouch screen, bigger battery, 16/32gb of flash, maybe more RAM than the touch, BT, a docking station to charge and connect a USB HDD and a cheap 17/19" LCD... charge $500 for the handheld (16gb version, +$150ish for the 32gb?), another $50 for the dock, a $100 for a decent sized USB HDD (320gb or so), $150 for a cheap LCD, $100 for a BT keyboard/mouse set and you're up to $900-1000 for a device that would serve as a laptop, desktop, PDA, and iPod. Not the most powerful thing in the world, but it would certainly be adequate for my wife, me at work (and most of my co-workers) and be really, really cool. Take (and access) all your files everywhere you go... anywho, just my end of the week ramblings.