I don't undertstand why the four-way direction keys are still not assigned to any function. Canon 400d has this, even Olympus E-500 (of my housemates)! Does that mean I should get a K10d or K20d?

I wonder. These all three cameras (400d, E-500 and K100d) are for beginners, right?
The RAW button is however something I wish for, and what's that green button? User programmed?