Of the presented choices,

andora1: wins hands down. Yes, we don't know how capable it's emulators will be yet but we do know PS1 will work well, and fullspeed SNES is a given (which it isn't on the GP2X unless you sacrifice effects and compatibility). For computer emulation (C64, Speccy, Amiga...) the Pandora wins on account of having a physical keyboard. On the productivity side, it wins on account of being able to run a desktop operating system with lots of common applications like word processors, web browsers and email clients, as well as network tools and other utilities. It's open (in terms of development) as opposed to the PSP.
And while it's true that you can buy a notebook or even an eeePC that will cope with emulation just as well as the Pandora, a notebook or eeePC lacks dedicated gaming controls and doesn't fit in your pocket, while the Pandora has everything you'd expect from a notebook, plus gaming controls, a small form factor similar to the DS, and full connectivity and good expandability thanks to USB Host.
I know which one is getting my money...