Division occurring the small format UMPC market
1)Flash memory smaller capacity and slower processor UMPC often running non windows software like linux. with a low price tag.
2) Rich media more powerful devices runing windows based software with huge conventional micro drives and more powerful processors .
Toshiba one of the major suppliers of micro format hard drives (Toshiba) who interestingly don't make a UMPC have just announced huge micro format hard drives http://www.engadget.com/2007/12/14/toshiba-intros-five-capacious-new-1-8-inch-hard-drives/
which will add to the division buy which type meets your need but remember the future is mobile !!!