Bryce Dallas Howard and Rachelle LeFevreSink your teeth into this, 'Twilight' fans: Bryce Dallas Howard has replaced Rachelle Lefevre as the villainous vampire Victoria in 'The Twilight Saga: Eclipse.'

What do you think of this casting shakeup? Sound off after the jump, then check out our rundown of everything we know about 'Eclipse' so far. img align="right" alt="Bryce Dallas Howard and Rachelle LeFevre" border="0" hspace="8" src="" vspace="8" //>Let your fangs chew on this, 'Twilight' fans: 'Terminator Salvation' star Bryce Dallas Howard has landed the mouthwatering role of villainous vampire Victoria in the 'The Twilight Saga: Eclipse,' the third film based on author Stephenie Meyer's beloved vamp-on-human romance series.

But hold on just a bloody minute ... doesn't the part of Victoria already belong to Howard's fellow redhead Rachelle Lefevre? Well, it did in the first two films, 'Twilight' and the upcoming 'New Moon.' But sources at Summit Entertainment confirm that Howard is stepping in to replace Lefevre, who had to drop out due to "scheduling conflicts" -- reportedly caused by her recent casting in the Paul Giamatti dramedy 'Barney's Version,' which begins shooting on Aug. 17 (the same day 'Eclipse' is scheduled to commence filming).

It's a shame, too, because Victoria gets some serious screen time in 'Eclipse,' as her vendetta against Edward Cullen (Robert Pattinson) and his ladylove Bella Swan (Kristen Stewart) takes center stage. For the uninitiated, Victoria is just a teeny bit pissed at good-hearted vampire Edward for dispatching her mate James (Cam Gigandet) in the original film, and therefore assembles an army of newborn vamps to terrorize Seattle and exact revenge upon Eddie by murdering his No. 1 gal Bella.

New Blood
In the only other 'Eclipse' casting news, 24-year-old Australian unknown Xavier Samuel has nabbed the role of Riley. A college student and "newborn" vampire, Riley is obsessed with Victoria and joins her in the plot to kill Bella.

Clean Slade
David Slade is taking over for Paul Weitz at the franchise's helm, continuing the trend of bringing in a fresh director for each film (Catherine Hardwicke directed the first). After proving he could create a spine-tingling thriller with 'Hard Candy,' Slade put his affinity for vamps on blood-soaked display with the 2008 romp '30 Days of Night.' Expect his 'Twilight' go-around to be spectacle-driven and probably a bit more hardcore on the violence.

Three's a Crowd
In the third film, the Edward-Bella-Jacob love triangle comes to a head, as Bella Swan confronts her feelings for both vampire Edward Cullen and werewolf Jacob Black (Taylor Lautner) ... and finally picks one. Who does she choose? We think you know.

The Write Stuff
Though the director has changed on each successive flick in the 'Twilight' saga, screenwriter Melissa Rosenberg has been a constant, having penned the scripts for all three.

Fast-Approaching 'Eclipse'
The next two 'Twilight' movies have boldly set not-too-distant release dates: 'New Moon' will rise in theaters on Nov. 20, 2009, while a total 'Eclipse' of the box office is scheduled to occur on June 30, 2010.