Mmm... Psion Series 5mx with Android...
Speaking as a former 5mx owner (back in the early-2000s), I still think the form-factor has a lot to recommend it. Resurrect the 5mx-type design (perhaps fixing the screen cable flaw?), add in a capactitative (AM)OLED touch-screen, WiFi, Bluetooth and other typical 2011 device features, and perhaps a "phone-friendly" Android version (Gingerbread?), and I'd consider one if I were in the market for a tablet.
Or maybe the Eee Pad Transformer is calling...