slytherin sides with Hogwarts?

[Jane Deau]

No: HPFGUIDX 104132

If I remember correctly, and if I don't I am sure someone here can 
correct me, didn't both Dumbledore and the Sorting Hat say something 
about all the Houses at Hogwarts will have to work together to defeat 
Voldemort? I think then that that will have to happen.

It seems by the seventh year Draco will be the (at least unofficial) 
leader of his House and for Slytherin to side with Hogwarts rather than 
the Death Eaters it may be because Draco has a change of heart.

Or everyone in Slytherin but Draco and his cronies side with Hogwarts 
and Draco ultimately suffers a terrible comeuppance.

Thoughts?

-Jane Deau