Various very spoilerish responses and a further question

[Phyllis]

SNAPE IS ESE SNAPE IS ESE SNAPE IS ESE SNAPE IS ESE  SNAPE IS ESE 
SNAPE IS ESE SNAPE IS ESE SNAPE IS ESE SNAPE IS ESE SNAPE IS ESE  

Kathryn:

<<And since Dumbledore's eye locked with Snape's I suspect he did 
know about the potion but regardless Dumbledore asked him to do it 
(you don't actually think he ws pleading for his life? I mean come on 
that was obvious surely).>>

I think it was obvious that Dumbledore *was* pleading for his life, 
and the only way I could believe something to the contrary is if I'd 
just imbibed a large dose of Alan Rickman Befuddlement Draught.

I think Dumbledore had finally realized that Snape was double-
crossing him, and that's why Dumbledore appointed him to the DADA job 
(and I think it had something to do with their row as well).  
Dumbledore (unlike Snape) knew Voldemort had jinxed the job, so by 
granting Snape his heart's desire and appointing him to the job, he 
ensured that Snape would only be spending one more year at Hogwarts.

Dumbledore put the freezing charm on Harry so Harry wouldn't enter 
the fray that Dumbledore suspected was about to ensue.  Dumbledore 
would know that if he died, the spell would be lifted.  And knowing 
Harry as he does, if Harry witnessed his death, Harry surely would go 
after Snape - thus thwarting the entire reason Dumbledore put the 
charm on him in the first place (to protect Harry).

Dumbledore tells Harry in OotP that everyone else's life comes second 
to Harry's.  In HBP, Dumbledore shows Harry that his (Dumbledore's) 
life is included in that - by saying that Harry's blood is more 
important in the cave, and by freezing Harry rather than defending 
himself at the top of the Astronomy Tower.  Why would Dumbledore put 
Draco's life over Harry's, then?

Why would Dumbledore want to die when he knew the magnitude of the 
task ahead: the number of horcruxes left to be found and destroyed?

And I don't believe that Dumbledore was on death's door, either.  He 
knew he needed help to fight the effects of the potion, but he wasn't 
done fighting yet.

~Phyllis