You know looking at that picture really makes me think it could be done!
Some of the Characters in that pic look a little to young when there supposed to be a teachers age (Ie Snape and Sirius). I would recommend MADHOUSE STUDIOS to do the animation. I know people are hearing me say that and are going WAAA!? Since there the ones who animated the recent fanservice fest Highschool of the Dead. But they also are responsible for some recent series they've done with MARVEL COMICS they’ve covered Wolverine, X-men, and there most resent...freaken BLADE!!.
I do have a problem with Hermiones look though. Her hair is to much like Taigi Aisaka from Toradora. Way to cute and cuddly. Hermione is just not moe. Hermione is a Tsundere, straight up!
I’m fine with everyone else looking that way. Although I would say Ron looks a bit to pretty boy in that picture. And I agree Ginuy does look like Orihime minus the boobs. I would love to see a little bit of fanservice of her.
And then there the topic of the voice actors and how it would sound in japans. Could you just imagine what it would sound like if they added the suffixes. I know there well be people who well have a problem with Ginuy calling Harry “Harry-kun” or Ron calling Hermione “Hermione-Chan”. And then there's the epic “Voldamort-sama” rofl
Oh and ummm... no concept drawing for “he who must not be named”?.