The current version needs to be improved to be ready for general release:
In other words, if I wanted to schedule lunch with you, I would submit my appointment, and JavaCal would inform you that I want to do this. This can be done by maintaining some state on the server end of pending confirmations, etc. If all is good, then both of our calendars are updated. If not, then I would be informed appropriately.
Project to be completed in collaboration with Mazahir Songerwala.