Tom Hiddleston will play Loki in Marvel's 'Thor'

Casting comic book characters is a tricky business. The better known the character, the bigger the minefield. That's why I think casting the (basically) unknown Chris Hemsworth as Thor / Don Blake, which Erik Davis posted about on Saturday, is a good bet. And once you've cast one unknown in the lead, you might as well get another unknown for the second lead, which is exactly what Marvel has done. Tom Hiddleston will play the trickster Loki, Thor's adopted brother and principal foe since childhood, in the upcoming film version of Thor. Sorry, everybody who was pulling for Josh Hartnett.

The news was broken by Nikki Finke at Deadline Hollywood Daily shortly before Marvel posted their press release. Hiddleston previously worked with director Kenneth Branagh on the London stage production of Chekhov's Ivanov, and acted with him in the BBC mini-series Wallander. Now we have an unknown Australian and an unknown Brit playing Norse gods! Thor is not due out until May 2011, though, so that should give the actors time to become better established. Hemsworth is currently filming The Cabin in the Woods, due for release next February, and also snared the lead in the Red Dawn remake, which should be out in September 2010. And it's likely that Hiddleston will show up in something else before Thor as well.

Casting unknowns / lesser knowns as comic book characters sometimes works (Christopher Reeve in Superman) and sometimes doesn't (Brandon Routh in Superman Returns). What do you think? Will Thor's unknown leads help or hurt the film?