I don't know if this is true but according to wikipedia there are two new characters to first appear as playable characters in the Mario Party series have been confirmed to be: Blooper and Hammer Bro.
here is the site http://en.wikipedia.org/wiki/Mario_Party_8
Personal I would rather see ShyGuy in Mario Party 8 then Blooper, But thats just my opinion.
Here is this list of characters in Mario Party 8:
Oh This has also been comfirmed by nintendo power!
here's the site: http://www.nintendopedia.org/index.p...=Mario_Party_8