Rob Bushway data-mined the buzz about Origami to reveal that a lot of Tablet PC users don't carry their existing Tablets around as much as they might claim. It's a good catch. I have 3 Tablets (how ridiculous is that?) and have to admit in all honesty that somewhere over 90% of my work on them is done in desktop mode. For something to be carryable requires an incredible fine-tuning of features. I never carry around my Toshiba Portege M200 (a convertible) -- that's the role of my Motion Computing M1400 slate (which shares the form-factor of my third tablet, an M1200, which is gathering dust, quite honestly). It's not that the M200 weighs a few more ounces (although it does), but the balance. The Motion Computing slates are really, really appealing for carrying around -- the M200 just doesn't feel the same way.
On the other hand, what do I carry around all the time? My Pocket PC Phone Edition PDA (an O2 XDA) which I like much more than my now-bricked SMT5600 Smartphone. Its got instant-on and battery life long enough not to worry about it. If only it had Shapewriter / Shark text input I'd be in heaven. (By the way, the "coming soon" version of Shapewriter has been that way for a year and a half: could IBM be holding back because Microsoft has so much to gain from a great mobile text input technology?)
On the other hand, the view-anywhere screen on the M1400 is better than that of even my PDA. But it's only 1024 x 768, while my M200 is 1400 x 1050.
In other words, there are a million (or at least a dozen) tiny little things: balance, screen readability, resolution, accessories, battery life, text input speed, etc... that weigh into the decision to carry a computer at all times. It seems to me that it's more a case of time and luck than anything else, that eventually there's going to be some piece of hardware that really hits the sweet spot. Whether the Origami / UMPC is it, I don't know -- the base resolution of 800 x 480 makes me doubt I'll be using it to compose articles.