Cordless ones are fairly common (on a different topic, I actually just bought a cordless Dremel, which is about the same size as a stick blender, and it's brilliant).
I know Kitchen Aid have one, but I don't want to base my decision on brand alone. I'd like to hear from others that have used them.
My reason for going cordless is that the place on by bench where I do most of my prep is on an island bench and not near a power outlet. It's in easy reach to everything else though (bowls, cutlery, spatulas etc...). It's also where the cooktop is, so if I wanted to quickly blend a sauce that is on the stove, I can.