Don't get your hopes up too high! :p
More information,
It's being developed by Nd Cube:
The company is now headed by Hidetoshi Endo, who was the former President of Hudson Soft. In addition, the key employees of the Mario Party team at Hudson have also joined the company. Nd Cube released Wii Party for the Wii console in 2010, and are currently developing Mario Party 9 for the Wii set for release March, 2012.
I actually enjoy the Mario Party series but haven't played one since mario party 5 (one of my favourite gamecube games)
It's a shame my Wii is currently broken!