Twitter Ticker is a new feature that can overlay a real-time Twitter feed at the bottom on your screen. Another new feature allows you to find out an artist and title of a song being played by clicking Track ID on your remote. Users can then share the info to friends via Twitter.
You can get the firmware update via your Sony Bravia if connected to a network (wireless or ethernet). Or, if your set is off the grid you can download the update from the Sony Support website, copy to a flash drive, and run directly from the USB port.
You can find some high quality stuff on youtubes 4k page:
http://www.youtube.com/playlist?list=PL5BF9E09ECEC8F88F
The 1080p should be enough to test but try the 4k out for kicks.