With Christopher Heyerdahl (2nd Alastair) starring in The Twilight Saga: New Moon, Jodelle Ferland ('Melanie Merchant' in "Provenance") has just been cast to play in the third Twilight movie, The Twilight Saga: Eclipse, as a vampire who has just been turned.
The Twilight Saga: Eclipse will open in theaters on June 30, 2010.
Source: ComingSoon.net, Fangoria.com.