Well, to no surprise it's now official. The NHL has announced that the 3rd outdoor NHL game will be played at Wrigley Field Jan 1, 2009 at 12:00 P.M. Blackhawk season ticket holders will have the option to purchase tickets for the game. There is a FAQ about the game in the link below. There is a specific question about Cubs season ticket holders ability to get tickets, and the answer is:
"The Blackhawks have no information regarding Cubs season ticketholders and access to the Winter Classic."
You can also sign up for email updates about the game. Sounds pretty "cool"