According to Gaming Age, insider sources are saying that THQ will buy out Midway.
Gaming Age is reporting that the deal between THQ and Midway has been in the works for months now. The recent restructuring to dump Midway's arcade division and make them a console only company seems to have been part of this. Gaming Age says that official word and more info will be coming Monday. Check the related link for full details.
How does this affect the GameCube? Not much, as it doesn't seem like much has change. Both THQ and Midway had confirmed support of Nintendo's next-gen system before. Perhaps we'll find out more when official announcements are made.