Well, I wouldn't mind if the keyboard was not perfectly centered. I don't care at all, actually, as it won't change usability (software side may, however, change usability a lot). But I would have no use of the joystick anyway.

Perhaps some hard keys could be sticked in the extra space, like small on/off switches that could be later assigned to functions of the default Settings application via scripts (WiFi, 3G, prevent autolockscreen, profiles on a 3-position switch, and so on)? Something like that, or smaller.