First, it will introduce the new system of multiple firing modes. Weapons won't be limited to just 2 attacks, we'll actually be able to have pretty much as many different attacks as we want. Weapons will have default primary and secondary attacks, and special keys will let the players cycle their fire and altfire buttons through all the available attacks. For example, an assault rifle might have the options of semiauto fire, 3-round burst, and full automatic. You could choose any of of those three to be your primary attack, and any one to be your secondary attack.

The other thing the code rewrite gives is the ability to use two different ammo types in the same gun. For example, an assault rifle with an attached grenade launcher.

This is just one of the many new features that will be included in the 1.0 release.