A new system software update (v4.00) will be released this week. In preparation for the launch of PS Vita in Japan, this update will prepare the PS3 to serve as a content management device. It will allow users to copy their media content such as games, music, photos, and videos between PS Vita and PS3, back up PS Vita save data to your PS3 hard drive, and update the system software for your PS Vita system using the network features of your PS3.
Other changes to take effect with this update include:
PlayStation Plus members can now choose to enable or disable each automatic update feature
Recommended games and videos
Sync trophy information
New PSN privacy settings for filtering friend requests and messages
You can find more details at eu.playstation.com
For a jump to the big 4.00 that update is terrible. No real great feature there. All my opinion of course but theres normally something to shout about in big jumps to the next number.