Axiotron originally began marketing the devices as a "TabletMac" as referenced in this 2007 press release and filed a trademark for the term. Sometime in the past year, however, the trademark was transferred from Axiotron to Apple, and Apple is now listed as the owner of the trademark.
Transfer of ownership may not mean Apple has plans on using the term. Apple may have simply contested the trademark due to the potential for confusion between "TabletMac" and their own trademarks. But now Apple could potentially release a product called the TabletMac, and given the overwhelming number of reports of an Apple-branded tablet device, it certainly raises that question.