Turns out Call of Duty 3 isn't the only third-party title to lack online support for the Wii. According to a preview of Tony Hawk's Downhill Jam running over at IGN, no third-party titles will be online compatible until 2007.
"Activision would not say why, but IGN has separately learned from multiple development sources that Nintendo will not release Wii Wi-Fi Connection libraries to third parties until early 2007, which means that no third party launch title will have an online mode."
Ouch. While the most attractive titles launching on the Wii are those done by Nintendo themselves, with high-profile third-party launch titles such as Call of Duty 3, Madden NFL 07, Far Cry, and Red Steel that depend as much on a robust online experience as well as a strong single-player experience, this is sure to be a big blow to Nintendo's launch lineup.