Sample databases are definitely an exercise in balance. You want to show off new features. You want stability. These two requirements are sometimes mutually exclusive. Perhaps a base schema is part of the answer, and naming the feature-specific versions with easy-to-identify names. No, the Production databases will not be named in this fashion. But this is a demo database. Is it that important to cram all the features into one version? I think not.
I worry about all the demos using AdventureWorks recorded in presentations. I think it was a difficult switch for many when people had to go to codeplex.com to get the sample databases. Not everyone is familiar or comfortable with the idea of downloading a demo database from somewhere else, especially when they've effectively been trained to expect the sample database in the installation process.
My thoughts / suggestions:
1. Commit to a location store sample database files forever.
2. Create multiple versions of sample databases that highlight specific features. Name them accordingly. Include basic and more-data OLTP, basic and more-data ROLAP, and others.
3. Invest time producing training on how and where to obtain sample databases.