Negative on both of those. They're both great characters, especially as stars, but having Luigi would feel like a PM/M&L series merge, and Yoshi has already been a partner. As said before, this game needs some original, new, creative partners.
Rosalina > Daisy - People who agree: 14 "Crystal Stars? They sound like great world-conquering tools! I want 'em!" Bowser, PM:TTYD
i have always really like luigi but in a paper mario game i dont want him as a party member. having a yoshi would be righteous. though id prefer not Mario's yoshi (the green one you always see) but instead a new yoshi.
Why, the only things they can do are Scratching, Tackling, Growling, Howling, Tail Wagging, and Pounding each other. --dragonman13 on pokemon behavior.