Killing SPID while delete canceling

First, I was running an unusually large delete about 60 million rows. It was taking much longer (18+ hours) than I expected so I went to Cancel Executing Query. Now, this is taking a while, which I expected it to (about 2 hours now)....
now the question is, is there any harm in Killing the SPID while the Query is canceling?
I wouldn't think killing the SPID would harm the rollback, but I am not sure of this? Any thoughts of how harmful killing an active SPID which is supposedly canceling a delete would be?
moved question to SQL SERVER 2005 FORUM