License Validation is a replacement for Hardware Locks. Some Rhino 3.0 licenses required hardware locks to run. These hardware locks were expensive for the customer, sometimes had difficult installation procedures, and slowed down Rhino.
All customers that would have required to have a hardware lock (primarily customers in Asia) will now be asked to validate their Rhino license. In general, this should be much less painful than getting hardware locks to work.
The only piece of information used during license verification is your CD-Key, which is included when you buy Rhino. Registration is not required, nor is any personal information. No computer-specific information, or information derived from your computer is sent to Robert McNeel & Associates.