We are upgading our Unity 4.2 to 5.0 is a new license file required?
If you go to Product Upgrade Tool - http://tools.cisco.com/gct/Upgrade/jsp/index.jsp and enter your Unity SASU contract number, the product entitlement page will come up for Unity 4.X to 5.X upgrade. The upgrades are separated by 32 ports and below versus 33 ports and above. I just received shipment of my upgrades. The 33 ports and above comes packaged slightly different, but contains the DVDs, documentation, and most importantly, the PAK for registering with Cisco licensing. Shipment of the upgrade licensing for 5 server took about 10 days.