DR.com has posted a teaser set report for Half-Blood Prince and they mention Matt/Neville in it:
Neville Longbottom is one character that kind of takes a back seat in{nl}this release, but he is still here and there throughout theproduction.{nl}”Neville is not officially in this story because obviously the book was{nl}just so big and there’s a lot of story to fit into the script, which is{nl}just a two-hour film. So, a lot has to be taken out unfortunately, but{nl}Neville is still there and is still doing his best with the Dumbledore{nl}Army and trying to fight the good fight. He sort of becomes involved{nl}with the whole Slughorn group and Slughorn’s party. There’s a really{nl}nice thing where he’s going to be a waiter. I tried on the outfit{nl}recently and he looks like he’s working on the Titanic with the color{nl}and the lapels and things. He looks really funny, and so that’s going{nl}to be quite nice. He’s just still being Neville and helping out as best{nl}as is possible, which is quite fun,” says Matt Lewis.
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