The next Titanfall update will include a a Featured Game Mode that will see new game modes added for a limited time only. The first of which is called Marked For Death, where a player on each team is marked for death. Players have to kill the marked enemy opponent while projecting their own teammate.
Another major addition is Titan Burn Cards. 14 new burn cards that amp/enhance your Titan abilities. You won't lose your Titan Burn Card if you die as a pilot either, just when you're in a Titan. Titans are also finally getting insignias. You'll be able to unlock insignias and apply them to your Titan. Something that should have been included from the start!
Other updates include improved matchmaking, three new Titan OS voices along with more VO warnings, Titans using ALL their abilities when in Auto-Titan mode now, and an increase in your Burn Card deck size.
The Titanfall official site details all the updates, plus all the bug fixes too.