I recently faced the same decision. Because I need actual word processing and spreadsheet-making capability, I passed up the iPad and opted for the new MacAir. It's lightly and very portable, but has a lot more computing capability. I did buy the external SuperDrive to make it easier to load disc-based software and to burn DVDs for friends and clients (I do photography, too, and deliver product on DVD).

It's got great battery life and aside from a couple of luck ups, one that required a hard reboot (I thought that was a PC thing, but I took it into the Apple store and the sales guy I talked to fixed it with a quick software update), it's been a superb tool for me. I highly recommend it.

Roxy