Reason for Attention/Hype;
1) Is is developed by Nintendo. Nintendo makes really good multiplayer games.
2) It had the potential to be something new an interesting, as opposed to a sequel that feels the same, with better graphics.
3) Nintendo needs new exclusive franchises and unique games for the WiiU.
If it were a 3rd party game, it would most likely be a discount/download game. No 3rd party studio would be able to invest the time/money/advertising to make it a $60 retail game.