Perhaps downloadable mansions after the main story? It would definitely extend the replay value of the game

Oh god, additional DLC mansions... *drool

I'd venture a strong guess at DLC for this. Unless there's a hidden co-op component, which could be cool.

10 bucks says all it is is just a online Leaderboard <_

I'd take $5-$10 (depending on length) downloadable mansions.

don't give them horrible ideas!

Wow, I'd actually be down for some DLC (or AOC, as Nintendo prefers) for Luigi's Mansion. Make it $3 or $4 for additional stages/mansions as side stories to the main game...and I'll dig in as soon as it hits the eShop.

Also, your avatar is rockin'. :)

Dark Moon? what if Luigi fought the moon from Majora's Mask?

Your friends' Miis can show up on the mansion family portraits. Boom, wifi-enabled! bullet point for the back of the box.

That...is...actually sort of a cool idea...

Maybe there will be an online multiplayer mode of some sort? Maybe it will be like the zombie mode in Call of Duty, except instead of zombies it would be endless waves of ghosts.

You know multiplayer mansion talking isn't really that bad of idea.  In fact I think its a pretty good one.  Especially if its easy for friends to just jump in online.