All I could say, is that Wii Party is NOT a Mario Party killer. One of my friends imported the game, and we played it today. The island board is all luck based, even though I won the first time playing. XD the minigames are in some cases really good, but in others it's so short and boring. Like one of them you have to take one pic of a UFO flying around, and you only get one chance to get it as near to the middle as possible. And you can't even chose the Mii's you want to play against, you face off with staff-created Mii's. They don't even have voices eather. Though, the Globe board is really fun.
But after playing it for 3 hours, I can tell you that it's not a Mario Party Killer. Hopes for another Mario Party shouldn't be given up just yet.