A number of people have become confused about what a Microsoft Smart Display is, compared to a Tablet PC. My friend Christian Verdonck has created this useful comparison table:

Tablet PC	Smart Display
Runs Windows XP Tablet PC Edition	Runs Windows CE for Smart Display
Complete (actual) computer	Remote Desktop for an existing Desktop Computer
Mobile, can be used anywhere	Needs to be connected to WLAN that's conneted to a PC
Not as light as S.D., contains all computer components (HD, memory, etc)	Very light, flat display and battery
Good Battery Life	No hard disk or powerful CPU means even better battery life