@Too late. Too expensive
Too late compared to the TouchBook, which is currently on backorder with no known sight of when the product will actually ship, still running a beta OS? Compared to firm availability of the Archos 9 in a little under a month with a finished OS on it (before the anti windaz fanboyism, win7 *is* decent and *does* run very quickly).
The TouchBook's battery life also assumes the keyboard (aka supplimental battery pack) is connected, in which case you may as well just buy a normal netbook and be done with it - Without the keybattery, the Touchbook's battery life is nearer 4 hours, around the same as the Archos. Being as the purpose of the Archos tablet is to be a tablet that's small and light (at 28 ounces it's half the weight of the TouchBook) comparing battery lives without massive external battery packs attached is fair.
The archos may also not have an SD card, but having 60/120GB of internal storage instead of... uh.. none on the TouchBook makes up for that, imo.
A minor detail that el reg's prreview missed was that the Archos also includes a dvbt tuner and antennas, so that's freeview viewing and recording directly on the device.
Pretty much the only thing the TouchBook does have going for it really is the price, and when comparing the two devices fairly (as you havent) it's clear why it's so low.
The Archos does have it's minor drawbacks preventing it from being pretty damn perfect (no 3g being the biggy) but it's really looking like being the closest thing to a "real handheld computer" of a tablet that's come along in a very very long time.