One more item on ThemeClick.com on this category. Network Posts plugin will let you display recent posts from all of your WordPress Network sites on your main network site. Plugin includes widget that one could simply drag and drop in the sidebar or page footer.
Advanced users or/and developers can make use of Network Posts plugin public methods to create custom page templates like they would normally do for a single site installs.
Plugin is suitable for large networks. Please, note that this plugin only works with WordPress Multisite setup. We are sure after from the success installation from this item Network Posts to your website you will be very satisfied