I've installed UG NX3 under Parallels Desktop 3.0 Build 4560 using the configuration required by General Motors. After turning off DirectX emulation (the Java-based launcher used by the GM toolkit refused to display itself properly), I was able to start NX3 and work in it. I see that there's a claim that CATIA v5R16 has been tested. OpenGL emulation is critical in order for these higher end CAD programs to perform to a point where they can actually be usable. I tested NX3 under Fusion and it was not usable at all -- try selecting a surface or solid in 3D modelling and you'll notice that Fusion's lack of OpenGL emulation will keep you waiting.... for a LONG time.
Be aware that I've only done limited testing with NX3, so it may or may not work for you.
Be aware that I've only done limited testing with NX3, so it may or may not work for you.