It might not be as bad as all that.

Seeing as they're physically all the same keyboard just with different labels, games shouldn't be a problem as they would probably let you define your own keys. And even if games didn't let you redefine keys, the operating system almost certainly would let you switch to another country's layout.

In any case arrow keys are misleading IMHO. A lot of people like me grew up with 8-bit computers where keyboard controls would be a layout like:

O = left, P = right, Q = up, A = down

because it let you spread the functions all over the keyboard which made gaming easier.

I would imagine something similar would apply to games on the N900. It might be different on such a small device, maybe something like Q, Z, H, L or something but you get the idea.