Sorry if it was allready asked, but is it possible to know which viewport the mouse is over, and modify the direction of the nudge according to it.
I mean if:

- the mouse is over the top view, right and left arrow 'nudge' on the x axis, up and down arrow on the z axis
- the mouse is over the front view, right and left arrow 'nudge' on the x axis, up and down arrow on the y axis
- the mouse is over right view, right and left arrow 'nudge' on the z axis, up and down arrow on the y axis

do you see the idea ... looks more natural for me, but maybe I'm alone :P

of course the perspective view require the 6 keys, like it is mapped now (page up page down for y move)