Since the N8 isn't out yet, which the N9 seems to be derived from; this is mere speculation. The USB port problem is at motherboard level, not casing design issue that leads itself to being fixed as aforesaid speculated.

In fact, the reasoning behind the N9... if that design is to be taken as real (it is unconfirmed at best) then it finally brings the Maemo products into design parity with other N-series products.

Typed on my N810