I think that a great new weapon would be a new medigun for the medic that would replace the syringe gun. It wouldn't heal people, but if shot at an enemy, it slowly drains their health.
After the Spycicle, Spies don't need any more anti-Pyro toys.
What I would like to see is a new Spy revolver that functions like a tranq gun: less overall damage, but slows the target for a short period of time and has a silent attack.

What do you guys think of this?
new sapper:
destroys buildings that are currently being built or buildings that are being moved instantly
-30% slower destroy speed on buildings that are already up