That depends on whether the definition of "new weapons" are new unique magical weapons, new weapon enchantments, or new mundane weaponry. I've done all three...
Some of my unique weapons are...
The Flail of Mechanus, created by the modrons to root out chaos in all its forms.
The Hound of Moradin, a warhammer containing the spirit of the Soulforger's prized hunting dog.
Mamoru, an intelligent sword concealed inside of a cane. He's rude, boorish, obnoxious and hits on every woman he sees.
The Munckin's Bane, created to smite the overpowered and rob them of their treasure.
The Five Deadly Venoms, a yuan-ti scourge that slowly turns its user into a tainted one.
My enchantments include...
Weapons of Immolation, which create a 10d6 fireball every time they hit an opponent. The wielder gets no save.
Weapons of Shadowstuff, which deal 2d6 negative energy damage to living creatures, heal the undead, and can produce darkness once per day.
Weapons of Dissolution, which deal a bonus 2d6 of non-elemental damage, and have a chance to disintegrate opponents on a critical hit.
Weapons of Holiness Beyond All Reason. They act as holy disruption weapons that emit holy water.
I'm currently working on shadowclaws, a nasty clawed gauntlet brazenly stolen from the movie Lupin the Third: Castle of Cagliostro.
Demiurge out.