Samsung has stated that the Android 2.2 update will be made available via its Kies software upgrade program. Kies is a desktop application that is currently only compatible with Windows. We presume that as Froyo hits areas like North America, it will also be distributed via over-the-air (OTA) updates, so OS X users won't be left out.
To date, nearly all of the significant Android devices have already received Android 2.2 updates; the Galaxy S will be one of the last major Android devices to receive it. The update will include:
Android 2.2 JIT compiler
Adobe Flash Player 10.1 compatibility
New Android Market with auto-updating
Speed improvements
Pinch-to-zoom homescreen flyover
Improved default keyboard
Quick links to “GPS” and “Auto rotation” toggles on notification bar added
Slightly different graphics and transitions with app drawer and default icon dock
Colored icons in settings
GPS Fix
Colored settings icons
Media Hub
Darker menu theme, navy blue color
Better Exchange support
Video records in MP4 format
New Search widget
New Gmail application
There's nothing particularly revolutionary about the featureset if you've used Android 2.2 on another device, but it's definitely good news for Galaxy S owners.
Disclosure: Samsung is a Mashable sponsor.