The latest trailer for Homefront: The Revolution was released and it highlights some of the new features for the title. Chief among these are the ability to modify your weapon on the fly and the "Guerilla Toolkit," which is their term for things like IEDs, a hacking tool, and an explosive R/C car.
Based on the narration in the video, each gun will have three configurable sections that allow you to create your own weaponry. You can turn a regular shotgun into a gun that lobs fire at the KPA, or make your pistol into an SMG. This kind of modification will be possible in the single-player campaign as well as the co-op mode. There seems to be an emphasis on using this system along with the special items from the "toolkit" to plan ambushes to take out the KPA rather than go for a head-on fight.
Homefront: The Revolution launches May 17 and will support up to four players online in the separate "Resistance Mode."