The new demo weapons:

[Shakermaker]

Not to mention the Soldier's extra gun he will get from winning

It hasn't been confirmed that the 7th item is a gun, or even a weapon. It could be a bagpipe for all we know.

 

[Sheepo]

This one weapon that I haven't tried is 100 times better then these other weapons I haven't tried.

 

[Letters]

Sounds pretty awesome... I just played a for a little bit to contribute 30 kills for the demomen.