I apologize in advance if this has been discussed before, but something that's intrigued me for a while now is the idea of an EarthBound Wii.
With Nintendo's development of the Wii's "Mii" character designer, and the intention to fully utilize the feature to its fullest extent, I see EarthBound as a perfect entry as a full AAA title with none other than your Mii character playing as the hero. EarthBound had this loosey-goosey-it-doesn't-have-to-make-sense flavor to it, which is precisely what the Mii characters (and the Wii for that matter) is pushing.
Character models within the game would be replaced with Mii characters located on your Wii(for example, your Mom, you Dad, your brother Tim, etc) or other Mii characters that you've met on-line before(per the recently revealed abillity of other players Mii characters infesting your plaza). Any Mii characters that the player doesn't have are replaced with generic Mii characters the game designers pre-built. These pre-built Mii characters by the way could also be "viral" also, in that they could leave EarthBound and go to your plaza, only to meet up with Mii character in Animal Crossing Wii, etc.
Just imagine: Instead of one of the cronies in the game being yet-another-boring-character, it could be your brother, your best friend, even your Dad! This would create some rather humorous results as you play through the (mostly) scripted events in the game where your own friends play the parts as shop owners, heroes that can party up with you, or the dim-witted enemy you constantly have to fight.
Gameplay would obviously be some sort of RPG engine fused with the Wiimote's gesture system, so you could for example Swing a Bat, hold a Teddy Bear in front of you to block an attack, or repeat strange patterns on the screen to pull off Psychic attacks. Throw in the abillity for up to four of your friends to join your party, and you've got a seriously addictive RPG game in your hands. Weather in the game could be dependant on your own local weather, TV's in the game could be a direct link to the Wii's "Weather Channel", secret NES, SNES, and N64 games could be scattered across the game's towns allowing you to "borrow" some VC games within the game. Companies could advertise within the game so that you walk into an in-game McDonnalds to get some hamburgers for healing(and fattening), or go to a Best Buy and pickup some items that unbeknowest to Best Buy can actually become powerful weapons(The long loading times of the PSP will cause a monster to be stunned for 234 turns). There is tremendous potential to really create a wild, fun, and lighthearted universe with a semi-serious plot still hanging in there.
Going much, much further, the game could even be Nintendo's first Massively Multiplayer On-line game, but unlike traditional MMO's, would encourage families to play together. Don't take on the monsters of the server-universe yourself, bring your siblings with you and become an unstoppable four-hero team. Human characters(friendly or otherwise) throughout the MMO game would actually be a mixture of millions of player's Mii characters leaking into the game to create one incredibly changing world of characters.
Obviously there are flaws, etc, etc, but I thought the concept was too interesting to dismiss. Let me know what you think.