I think that if they were to introduce a convertible tablet, I would buy it (especially if they can keep the same dimensions as the current offerings) but I would much rather see one that had a removable screen. Personally, I don't think it would be that hard from a technical standpoint, and it would give them made bragging rights.
First dual processor laptop (I think that this is true)
First laptop with a removable screen
First laptop with 3 wireless cards standard
See the way I picture it, once you remove the screen, a 1GHz or so ULV Core 2 in the display housing kicks on, along with about 2-4GB of flash memory and 1GB of dedicated RAM, the display housing also has an 802.11n card in it that creates an adhoc network with the base of the machine. The display would also have a battery good for an hour or 2 of life. So you can disconnect the screen, and then wander as far as many hundreds of feet from the base with just the screen, using it as a tablet. The onboard flash would be there for your applications, but the n link would be some you can access the hard drive of the main machine, as well as a possible XGrid thing.
It would make the screen thicker, but think how cool it would be.