Here's a link to the Finale 2008 announcement:
It's not the official announcement from MM, but apparantly their web developers were working on this, and google found it.
There are many, many, many more included Garritan sounds from JABB, Marching Band, Choir & World libraries. All included with Finale 2008.
Here's the list of included sounds:
edit: MM posted the official announcement today. Here's the new links:
List of included sounds:
Looks way cool!