Rock Band goes 4G is another way of saying it goes mobile since 4G is a network which gives a better signal and speed compared to 3G.
Seems to be a bit of a theme lately, publishers providing video and screenshots to mobile games without any information to go with them, EA have decided to ‘announce’ that Rock Band is to launch on Verizon (US ‘cell’ phone network) 4G and there’s some screens. Enjoy.