Again, MicrosoftCorporation has the largest share of the market for TabletPc operating system.
The company has listed amongst the ten main benefits, the ability to use all features of WindowsXp (see http://www.microsoft.com/windowsxp/tabletpc/evaluation/toptenbenefits.asp).
One of the newer interaction methods made possible by the tablet PC is the ComComponent called DigitalInk?, which provides handwriting recognition. It also separately identifies handwriting ink from drawing ink. Ink can be used as annotation to regular documents via OLE.
Also it has gestures, which include speech recognition modules with support for Chinese and Japanese languages. Gestures can be custom constructed. See http://msdn.microsoft.com/msdnmag/issues/04/12/TabletPC/default.aspx.
Any body has recent news (e.g. 2004) on additional merits of a convertible TabletPC (one that can function as a laptop as well). Or is it going to remain a novelty item due to lack of killer applications that attract the laptop buyer?
http://www.eweek.com/article2/0,1759,1590939,00.asp seems to confirm the notion that the strengths of the TabletPc platform will be absorbed into notebooks, and what is left would be specialized cases. And WindowsLonghorn is not expected to have a version for the mobile market.
UltraMobilePC - UMPC
According to WikiPedia, this 2006 created category of hardware runs TabletPc operating system, and supposed to run some WindowsVista version when it evenuates. The product was codenamed Origami before its official release.
Instead of having an electromagnetic screens allowing interaction with a specialized pen, a lower cost touch sensitive screen is provided.
UMPCs have form factors between a PDA and a TabletPc and is priced between these ranges too.
PowerUsage is said to be a key shortcoming of UMPC, as users try to compare their experiences with a SmartPhone or PocketPc which typically do not have a spinning harddisk and myriad of applications.
Resources
MicrosoftChannelNine has a wiki page on TabletPc that has many links at http://channel9.msdn.com/wiki/default.aspx/Channel9.TabletPCs
Microsoft sponsored whitepaper on Business Case for Tablet PC at http://www.microsoft.com/downloads/details.aspx?familyid=abcf98ff-c1d0-4b83-a6c0-202a060c0073&displaylang=en
Development in managed and/or unmanaged code at http://msdn.microsoft.com/msdnmag/issues/04/12/TabletPC/default.aspx?side=true#a
User story on Vaio above http://jkontherun.blogs.com/jkontherun/2004/08/a_typical_day_w.html
For an insider's view on the current state of Tablet PC developement http://download.microsoft.com/download/0/f/7/0f7cc82e-df70-4ca0-a74d-5692c10e6c40/bill_gates_2005.wmv
...Optimizing UMPC Applications at http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dntablet/html/tbconsudokusamplefinal.asp