On the eve of its initial public offering, Zynga has kicked off some holiday marketing and launched a new mobile game, ForestVille.

Zynga is launching a promotion with singer Michael Buble, whose album is tops on the Billboard 200 chart for the third week in a row. Fans of Buble will be able to mingle with Buble’s avatar (pictured left) in Zynga’s CityVille game starting next week. They can party with his band as part of a holiday bonfire and get Buble-themed quests. They will also be able to access an exclusive video in CityVille, which has 49 million monthly active users.

Others that have made appearances in CityVille include Enrique Iglesias and the King of Pop, Michael Jacson. Meanwhile, Zynga has launched ForestVille for mobile devices. In the iOS game, users will be able to play in a magical forest where they can build homes for animal characters, create businesses, decorate, and connect with friends. This is Zynga’s sixth mobile-first game, launching soon after CityVille Holidaytown, Dream Zoon, and Mafia Wars Shakedown.

Still, considering that Zynga is hoping to raise about $1 billion at an $8.9 billion valuation or more, these latest moves aren’t particularly impressive.