Konami missed the boat with Guitar Freaks and Drummania. However, one year after Guitar Hero debuted, the thought may have crossed Konami’s mind. They registered trademarks for Drum Revolution and Guitar Revolution, which sound like the US names for Drummania and Guitar Freaks respectively. Both trademarks are still active, so it’s possible for Konami to use them for US versions or something else in the future.
But, I don’t think that will happen. Guitar Hero and Rock Band are already in stores and in the homes of many gamers. At best, the virtual rock game genre is competitive and at worse it's saturated.