If you want an in-depth look at the tools of Battlefield 3's trade -- which is to say, cap-busting -- these videos from YourGamingTeam should suit your needs. It's pulled from an early alpha version of the title, but still gives a decent demonstration of the game's customizable kits.
Built on the cutting-edge Frostbite 2 technology, Battlefield 3 aspires to be DICE's best shooter and biggest launch yet. Expect improved graphics, louder explosions and more smithereens. So many smithereens.