Weapon types:

Standard(this was all weapons before this update)
Swift(attack faster, deal less damage)
Heavy (attack slower, deal more damage)

all weapon types have equal DPS.

All dungeon weapons are Standard
All Fishing items are Swift
The "Guild Sword" is Heavy
The "Knight Sword" is Heavy
The "Bone Club" is Heavy

New items:
"Wooden Club" (Heavy)
"Forest Club" (Heavy)
"Cactus Club" (Heavy)
"Ice Club" (Heavy)

All items that are currently in your safe file will remain Standard.