Confirming earlier reports from the mouth of Mark Millar, Kick-Ass will indeed begin filming in Ontario, Canada in September, 2008. A notice posted on the website for the Ontario Media Development Commission states that the film will be filming in Toronto from September 20 to October 9.
Aside from the filming dates, the listing doesn't really provide any further information about the film.
Kick-Ass follows the story of a 15-year-old boy named Dave Lizewski who, despite living in the "real world", decides to become a superhero. The film was co-written and is being directed by Matthew Vaughn. Already signed to the cast are Aaron Johnson, Lyndsy Fonseca, Chloe Moretz, Christopher Mintz-Plasse and Nicolas Cage.