Machka and I each (yes, each) have a Hewlett Packard Pavilion dm1. We consulted one of Machka's colleagues in the computer department at her work, and he advised to get the most powerful processor you can afford. He said the tablets just didn't have it if you wanted to edit pictures using decent software, and because I am getting into videos, the same thing applied.
Now, the HPs don't have the processing power of the bigger and more expensive laptops, but it's better than the smaller netbooks. And it has expandable RAM, which can help a little with memory function on big files. We have yet to expand the memory, however.
It has a solid case (Machka dropped hers in a thin backpack the other day, and no damage ensued), a disc drive with decent capacity (360Gb), three USB ports and a nice screen, plus the keyboard continually receives good reviews (even from Machka who is quite picky about such things).
They're not the solution for everyone, but they will do us. And the price was super-right.
By the way, the ways things are pointing, if you want to add the next generation of peripherals to your current Apple product, or add your current peripherals to your next-generation Apple -- forget about it. Apple apparently is about to alter the design of the connection, and it won't fit any peripherals you've had before... although some bright company might manoeuvre their way through Apple's control-freak behaviour to produce an adapter.