For a 9 yr old to watch harry potter (including the new one) if they dont scare easily and they no it's all fake then i dont see why not.
And Sabby52. . .OzziesHunnie is right, if you think he was mature enough and understood it wasn't real then why would you get shot for it
It is for the parents to decide, each child is different, with me, mine is 4 and he's seen Harry Potter up to Order of the Pheonix however i will not allow him to watch half blood prince and the new deathly hallows, as i see them as too dark, i mean what happens to dumbledore in half blood prince is horrifying and he adores dumbledore so i dont my LO is ready for that one yet, theres alot of dark scenes in Askaban (i can't spell lol) and goblet of fire and order of the pheonix, and really only got away with those because he watches them but he doesn't watch them, he tends to have them on watch them properly for 5 -6 mins then he'll play with toys and keep looking back at the T.v and not really pay attention so i guess i'm lucky with that