If you have followed my previous posting, you'll realize that Sun Calendar Server 7 is seldom used in the real world.
Simple reason: No one will use a Calendar Server that cannot integrate with WebMail.
Efficiency has become the norm today. Everyone wants a integrated, tightly-coupled office productivity tool to work with.
At present moment, most Sun Java Communications Suite 7 deployment will still be using Sun Calendar Server 6, until Sun Calendar Server 7 is developed to interface with Sun Convergence Server (WebMail).
Because of the same reason, if customers require mobile sync feature, they'll need to deploy Sun Java Mobile Communications Server - an additional component with separate licensing model.