The DADA Position will bring out the worst in him... HBP Spoilers

[colebiancardi]

No: HPFGUIDX 133619

 
> 
> So given this, why would Dumbledore have finally broken down this
> year and given the position to Snape? He would have known that
Snape 
> could only do it for one year. Why would snape want the job? He's 
> smart enough to have figured out the curse... If LV hadn't told him 
> about it already. 
> 
> And, what does this say about Snape? If this year runs true to 
> pattern, Snape's true nature was revealed when he killed
Dumbledore, 
> and he has a very bad fate waiting for him.
> 
> Janeway

or it could be that Snape's true nature is loyal to DD and the OotP
and that will be revealed in book 7.