This is a free upgrade for all existing customers. In addition to the new Google Calendar syncing features, many bugs have been fixed and all users are strongly encouraged to upgrade.
Here is what's new in 2.0:
* Ability to sync iCal with Google Calendar, including the ability to map iCal Message alarms to Google pop-up, SMS or Email alarms.
* Option to filter out Alarms and To-Dos from subscribed calendars on your LAN
* LAN/WAN synching improvements, VPN compatibility, IPv6 and Back to My Mac compatibility
* Improved performance
* Fewer Conflict Resolver disputes
* Auto-repair of damaged iCal databases
* Improved error logging
* BusySync 2.0 is backwards compatible with other BusySync 1.5 users on your network