No. Apple will be focusing on two expandable software platforms to the near future: The iPhone OS and the Mac OS X. A tablet would need something different.
Also, why introduce multitouch as a great thing this year, when you have a tablet around the corner. Last but not least tablets lack good input methods. Virtual keyboards (iPhone style) are quite sub-optimal for text input and pens have rather recently been ridiculed by teh Steve, if I recall correctly. To to put it more bluntly: Text input sucks on tablets. And Apple seems to know that and I think it reflects in recent designs. They made a conscious (and probably right) choice for the iPhone, for the sake of screen size and portability, but otherwise went for just multitouch touchpads on the notebooks.
I think the problem with text input is a major obstacle for Apple. More so than for Microsoft, by the way.
I think, Microsoft's handwriting recognition and speech recognition is way ahead (!) of Apple's. Especially Vista compared to Leopard. I wouldn't be surprised if Apple needed to do some catching up at some point. Not near-term but rather mid- or long-term. And that could be really, really costly.