I'm in love with the Sony Vaio UX280P
Sony's entry into the UMPC market is spectacular, in my opinion. The UX280P features a bright 1024x600 4.5" touchscreen display, 1.2GHz Core Solo processor w/ Centrino chipset, WiFi 802.11a/b/g, Bluetooth, a slide-out keyboard, 1GB RAM, 40GB hard drive (although it's only spinning at 4200 RPM, which is fairly slow), and plenty of ports for extensibility.
As far as the price, $1899 seems a little high. That's why I'll be watching for some good sales and maybe waiting until they're $500 or less on eBay :)