Here's an interesting quote:
Note that there will still be lots of personal computers sold and in use ó in fact our casual estimate is that there will be 2 billion PCs in use by 2016, despite growing tablet sales. Thatís because tablets only partially cannibalize PCs. Eventually tablets will slow laptop sales but increase sales of desktop PCs. Thatís because many people, especially information workers, will still need conventional PCs for any intensely creative work at a desk that requires a large display or significant processing power.
Not sure if I really want a tablet at the moment, but every is walking around with an iPad. I still prefer my traditional laptop