Ethan Hawke is the latest name associated with the new version of Total Recall. The Len Wiseman-directed reboot stars Collin Farrell and will be released on August 3rd, 2012. Bryan Cranston, Kate Beckinsale and Jessica Biel have been previously reported as being cast or currently negotiating for roles in the film.
As for Ethan Hawke, The Hollywood Reporter states that his "role is being kept secret and it is cameo in nature". Given that the story is different than the original film, including no longer taking place on Mars, your guess is as good as ours in regards to what role he'll be playing.