The Flak Cannon is a shrapnel weapon. Primary fire sends shards of flak into whoever happens to be walking into your line of fire. The shrapnel will also go around corners to damage anyone who might be hiding there. The Shock rifle is also a familiar, but different fellow. It fires and energy beam that sort of explodes on impact.
Secondary fire sends a glowing ball of death.
UT's BioRifle is the new implementation of a Goo Gun, firing a blob of toxic slime that sticks to whatever it hits. Alternate fire shoots a bigger blob. Not much, unless somebody is chasing you and you lay down a goo trap. The snipe rifle also puts in a return appearance working pretty much as it did in Unreal. Zoom in with alt fire, squeeze off a round with primary fire.