[[Wikipedia:Maintenance]] used to say "There is a common misconception that only administrators can deal with Wikipedia:Votes for deletion." It seems there is still this misconception, and for some reason, that statement was replaced last July with the ambiguous "Non-admins can help keep deletion pages clean by resolving discussions." (I'm not sure what "resolving" means here, but I suppose it could be inferred to mean closing.
The rule at http://en.wikipedia.org/wiki/Wikipedia:Deletion_process#Non-Administrators_c... says "Non-administrators may only close decisions which are unambiguous 'keep' decisions" and unregistered users can't close them at all. This was added last June with little discussion - http://en.wikipedia.org/wiki/Wikipedia_talk:Deletion_process#Non_admins_and_...
Angela.