For those concerned:
Natalia Tena ("About a Boy") and George Harris will play Order of the Phoenix members Nymphadora Tonks and Kingsley Shackebolt, who help Dumbledore, the Weasleys, Sirius Black and others figure out what Voldemort's Death Eaters are plotting. Helen McCrory ("Casanova") will play one of those Death Eaters, and Sirius' cousin, Bellatrix Lestrange. Kathryn Hunter will play Dursley neighbor Mrs. Figg (who isn't exactly a Muggle), and 14-year-old newcomer Evanna Lynch will play a strange Potter ally, the moony Luna Lovegood from Ravenclaw, a role won in an open casting call that attracted 15,000 girls.