I wouldn't suggest this is the only personal computing device you'll ever need, though it will satisfy the needs of many of us as convenience when on the road. It is the new format of Ultra Mobile PC (UMPC) and it rocks!
There are a couple of these just making it to market or will be soon, my favourite (and it's on my birthday list) is the Samsung Q1. This link to Best Buy (U.S.A.) is the first I've seen online and with the Canadian dollar being so comfortably high, this is the time to buy and may be worth picking up on your next visit to the sunny south.
If you're trying to remain connected, in-touch, or simply looking for something capable but less than a full laptop, this is the toy, er, tool for you. With a 40Gb hard disk, full audio and video capabilities, and wireless features that allow quick connections anywhere, the package is a meet-the-needs solution for the traveller or business user. With on-board USB and media ports there's something there for the Photographer and the presenter too.
The biggest problem I anticipate for this pint-sized wonder is that software has become increasinging developed for larger screens and while this might pack a punch and run a full Windows XP-based OS, not Windows Mobile or Windows CE, How many applications will be problematic with this new standard.
Like a larger variation on the Sony PSP, with the freedom of running Windows applications and not requiring a specialized development platform (as is the case for Windows CE/Mobile) I can see this being popular in-office/workplace mobile tool. Especially at dealerships, service centres, doctor's offices, and other service-related situations.