A major feature of SharePoint Workspace 2010 (next version of Office Groove 2007), is a significant reduction of SharePoint Server 2010 bandwith and I/O overhead.
How?
Well, with the current SharePoint 2007 or MOSS server, when a user requests a 20MB Powerpoint file from the server, he requests the first time 20MB data. If he makes a change, he sends back 20MB to the server. With SharePoint Workspace 2010, when the user makes a change on the file, he only sends back the "delta of changes" thanks to the Synch Framework.
While this sounds obvious for a file, this becomes much more interesting while you are working on a "team project" made availble through a SharePoint micro site as this is also valid for instance for SharePoint lists.
This feature is expected to have a significant impact on SharePoint 2010 server farms.
SharePoint Workspace and Groove 
good point. You should do a presentation on it