You can download it from http://www.garmin.com/support/download_details.jsp?id=5286.
Note: This beta is English only and in fact will crash in other languages. If you are not running your Mac in English don't download this beta yet.
Changes made from version 3.1.4 to 3.2.0.7 Beta:
General:
* Added Activity-based profiles. This allows the user to have different route and map settings for different activities.
* Added ability to back up and restore user data
* Added heart rate and cadence to the track dialog
* Added the ability to export GDB files
* Added analytics to collect application usage statistics
* Removed ability to display marine maps in deference to the future release of HomePort
Folder improvements:
* Added folders and subfolders to allow organization of lists
* Add ability to sort user data by date in addition to the current name, type
Map improvements:
* Added Overview mini map, accessible under the View menu.
* Added tips to the tool pop up about moving waypoints or shaping a route.
* Added ability to configure which map features (POIs and lines) to show or hide.
* Added ability to configure the POI icon size
* Added ability to configure the number of labels that are displayed on the map
* Improved 3-D view to hide features that are behind terrain.
* Improved geocache support:
* Added ability to configure what is displayed for geocaches on the map: Symbol, Symbol and Id, or Symbol and name. Use the context menu to change settings for more than one at a time.
* Added support for Opencaching.com geocaches
* Added searching for Opencaching.com geocaches
* Added the ability to set the z-order (draw order) of BirdsEye and Garmin custom maps. Note this will only work with new BirdsEye images downloaded for devices with the latest beta firmware.
* Improved the ability to track the found status for geocaches
* Added the ability to read the geocache visit status from supported GPSs.
* Added the ability to automatically log found geocaches to Opencaching.com
* Added a new smart list criteria for geocache find status
* Improved import of geocaches from a GPX file
Fixes:
* Fixed issue where quitting the application while reading a map from card could cause a crash
* Fixed issue where disconnecting a device while it was being read could cause a crash
* Fixed rare issue where clicking on the 3-D map with the routing tool could cause a crash
Known issues:
* Find is not finished. As such, there is no way to turn finding of Opencaching.com geocaches off.
* Though your previous data will be preserved, this installer will overwrite your old version of BaseCamp. You can rename your current version of BaseCamp before you install to keep both versions. If you do overwrite it, but want to revert to the released version of BaseCamp later, download and install BaseCamp from our web or the Mac App Store and your old data will be available.
* Since BaseCamp beta uses different BirdsEye servers, that functionality will not be immediately available while using the beta. This will hopefully be rectified in the future.