Every time I see the Modbook mentioned somewhere, I get very intrigued. It would never measure up to my desktop system, however, for two reasons:
1) No keyboard, and I am a big keyboard shortcut junkie when using Photoshop
2) The screen is too low-res for me. I do my comicking on a 24" monitor at 1920x1200, and even that is a bit of a squeeze for me, since I work at 600 dpi and usually zoom in to 200%.
I could see using it for sketching, but I prefer sketching with a pencil anyway.
Still, very enticing.