Sarah Polley came to Sundance to promote the thriller Splice. Michelle Williams was there to launch Blue Valentine. But now they’ve got a reason to get together this summer. I’ve learned that Polley has secured the financing to direct her script Take This Waltz. Williams will star with Seth Rogen in the romantic triangle. The script made the most recent Black List of 2009’s best unproduced screenplays. Polley will set another actor shortly to round out the cast. The producer is Susan Cavan. Deals are coming together quickly for a July production start in Toronto, with an independent financing package that includes Telefilm Canada, private equity, and gap financing. That’s similar to Polley’s last directorial effort, 2006’s Away From Her which earned her a Best Adapted Screenplay Oscar nomination. Williams, who’ll next be seen in the Martin Scorsese-directed Shutter Island, turned in a Blue Valentine performance that has generated a lot of great buzz at Sundance. She stars with Ryan Gosling the brutally honest drama about the erosion of the relationship between a young married couple. Derek Cianfrance directed the script he wrote with Joey Curtis.