Every purchase of OoT 3D is a vote in favor of Majora's Mask getting the same treatment. It is your sacred duty to ensure a version of MM brought up to modern-day standards. Ergo, buy OoT.
Well, just took the plunge and preordered Pilotwings Resort, Steel Diver and SSFIV at Amazon, where I also preordered the Cosmo Black 3DS. I never played Wii Fly in Wii Sports Resort, so I'm looking forward to exploring the expanded Wuhu Island; the idea of hitting up thermals in the hang glider at night gives me cool Birdman vibes (PW64). Plus, there are interactive dioramas to collect, which entertains the collector in me.
Steel Diver looks like an immersive simulation -- the underwater volcanos and periscope battles in stormy seas look awesome -- and while I own both console versions of SFIV, the portability, combo shortcuts, over-the-shoulder view, collectible figures and 3D make it a buy for me.
What I'm looking forward to most, though, are the AR Games. I love how in Target Shooting (is that what it's called?), a large swathe of the real-life table surface flips when it transitions to the second level. It's also neat to see the ground bulging as the dragon statue pushes through. I think that'll blow people's minds... I've yet to see the billiards/mini-golf, or the shark portion of fishing. It's cool, though, that you can display dozens of Miis and/or videogame characters with the Mii Viewer and Star Viewer. I previously thought you could only pose one character at a time.
Between the 3DS, three games, Pokemon Black and MvC3, my wallet am cry... But it's an exciting time to be a gamer.