Well this news is sure to send some fans into a tizzy.  Deadline is reporting that Johnny Knoxville will voice Leonardo in Teenage Mutant Ninja Turtles and Tony Shalhoub (Monk) will voice Splinter.  These roles were motion captured on set with Pete Ploszek as Leonardo and Danny Woodburn (Seinfeld) as Splinter, but Paramount always considered using voice actors.  Whether this means the turtles Raphael, Donatello, and Michelangelo will also get voice actors remains to be seen, but now it's looking pretty likely.  Michelangelo does talk in the teaser trailer, but this may not be his final voice for the movie.

Not to be a total TMNT nerd, but if you assume that Knoxville and Shalhoub will be using their familiar voices (rambunctious and nebbishy, respectively), it certainly doesn't fit the characters as they've been depicted in the past.  Leonardo is the stern leader of the group while Splinter is the old sage.  Honestly, this kind of casting makes me more intrigued about what director Jonathan Liebesman is cooking up even if it flies in the face of that Ninja Turtles fans expect.  The film opens August 8th.  If you haven't seen it yet, hit the jump to check out the teaser trailer.

Here’s the synopsis for Teenage Mutant Ninja Turtles:

The city needs heroes. Darkness has settled over New York City as Shredder and his evil Foot Clan have an iron grip on everything from the police to the politicians. The future is grim until four unlikely outcast brothers rise from the sewers and discover their destiny as Teenage Mutant Ninja Turtles. The Turtles must work with fearless reporter April and her wise-cracking cameraman Vern Fenwick to save the city and unravel Shredder’s diabolical plan.