If you have a legitimate license and up to date maintenance, go to Siemens' GTAC website. You will need to establish a webkey account, for which a username/password should be in your I-DEAS license file.
Once you establish a webkey account, you can login and check the I-deas documentation that's online. Within that area should be some sort of What's New Guide, which will outline the major changes made in I-DEAS NX 5.
I could very well be wrong, but I do not believe there were any major changes to the interface other than allowing for a graduated color background and possibly eliminating some of the keyboard view manipulators (rotate, pan, zoom, etc.) in favor of using the mouse for that.
If you need help with the webkey, you can call GTAC for assistance.
Nissan is not starting production on I-DEAS NX 5 until Jan. 2, 2008 (based on the info I've received so far from NTCNA).
Tim Flater
Senior Designer
Enkei America, Inc.
Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.