According to Ultranauts.com the UMPC concept will succeed because there is Asia. Many people in Asia do not know how to write in their native language using keyboards - I have to confess that I did not know that that was possible - but they find the use of the TIP included in Windows XP Tablet PC Edition very comfortable because they do not have to learn "how to write"! Another reason why UMPC are popular in Asia according to this page is because in Asia they prefer small gadgets.
Hum... How many people do we have in China now? One thousand million? I hope that they are reading this. ;)