Shawn Blanc makes a convincing case for the iPad as the new laptop. It does most things you can do on a MacBook Air, it is cheaper to buy, the apps are cheaper, it’s smaller and lighter.
I agree with all his points except when he says that the iPad does not have to be pulled from a bag at airport security. This is definitely not the case in Europe where the iPad is treated as a laptop.
As he says, though, there are some things that are difficult to do on an iPad. He cites his need for a handful of OS X applications, such as Quick Books and InDesign, and some instances, such as handling Mail, where the laptop is still more efficient. I also find handling posts to MacFilos, in particular manipulation of photographs, is easier on the laptop.
There is also the issue of convenience. If an iPad is to be a replacement for a laptop at all times there are many occasions when it’s also necessary to carry an external keyboard. An iPad and wireless keyboard weighs the same as an 11in MacBook Air but the combination is considerably more bulky.
Shawn does have a very good case, I admit. In a year’s time, I imagine, this case will be even stronger as iOS becomes ever more competent.