DICE added Obliteration mode to the Battlefield 4 beta yesterday on October 9, 2013. It was first seen in a gameplay trailer of the beta on Xbox 360 by DICE (which still needs to be added) a few days ago. For whatever reason though the gametype isn't in quick match so to play you'll have to server browse it.
The beta ends on the 15th so if you want to try out the gamemode do it ASAP! -- 
awyman13 Talk Work 12:18, October 10, 2013 (UTC)