Update on April 22: The movie is set to open on either June 29th, 2007 (according to Yahoo! Movies and Rotten Tomatoes) or on October 26, 2007 (according to iMDB and AOL), and it's based on the novel by Dave Gerrold. A comment from Mark prompted me to look further into the plot, and that made me realize that the novel on which the movie is based seems to talk about the author's homosexuality, but it seems the movie will not. Here's what wikipedia says about the matter:
"An important difference between the novelette/movie and the novel, is the fact that David Gerrold was out about his homosexuality when he adopted his son. Current plans are that the movie will not include this information; however, the novelette does bring it up."
I'm still investigating the issue and will let you know more when I know more. [Thanks, Mark!]