Dark Horizons has Jim Broadbent on record as confirming that he will play Professor Horace Slughorn in the film of Harry Potter and the Half Blood Prince. This is the biggest no-brainer in the history of casting, so thank you, Warner Brothers and David Yates, for not screwing it up. Excitingly, so far we are one for one with the casting suggestions we made back in July! We expect Bill Nighy, Daniel Day-Lewis, and Ian McShane should be getting calls from their agents any day now.

Broadbent on "Potter" & "Indy 4" [Dark Horizons]
Earlier: Casting the Next Harry Potter Movie