If you're talking about new PCB Cad*ence studio (it includes ORCAD 9.2.3) then the improvements are really big:
- the SMA*RTROUTE still exists, but the new SPEC*CTRA is much , much better
- Instead of Layout you can switch to Allegro
- new libraries
But if you don't use autorouters (SPEC*CTRA is really amazing thing) maybe there is no sense to switch to the new version.