"Tablet" originally referred to a slate form factor about the size of a letter/A4 piece of paper running Windows XP Tablet Edition.

As far as pocketable computers, they were called UMPCs (Ultra Mobile PCs) but are now generally called MIDs (Mobile Internet Devices) or, if they have voice capability, smartphones.

The big news in pocketable solutions at CES is the Viliv N5 and UMID M2. Both run the Intel Atom processor and are 5" clamshells. Dell is also rumored to be coming out with some kind of small tablet but I haven't seen any specs. Apple won't be at CES but has scheduled an announcement event for late January.