It's seem that a lot of old 2-d game doesn't make automaticly a good 3-d game. I think about castlevania , rygar Megaman... do You think Kid Icarus should stay in 2-d like the last wario game ?

Well, you wont know until you try it. If a 3D Kid Icarus turns out not so great then yeah I would say the next one, if there is one, should be a sidescroller. Perhaps not taking the same direction as Wario Land: Shake it! but more like an updated Yoshi's Story type look.

Keep in mind that Nintendo are masters of transferring 2d to 3d. I think Kid Icarus should be 3D and would be great as it, since Nintendo haven't disappointed me with a 3d transition so far.

I would like to see a 3D version. The original Kid Icarus was done in the Metroid engine, and moving Metroid into 3D produced one of the best series I've ever seen on a console. Something like Metroid with flight would be great. As a semi related note, I hope it's not as hard as the original Kid Icarus was. I am not against games that are challenging, but Icarus took it to far.

i'd like to see it 3D for now, but I want to see it on the DS too. actually, I don't know whether I want it on the Wii or DS more...

I would like a 3D. In the beginning of Brawl..... i was just so awesome to control Pit.

I want something like that. It would be just awesome

2D on the DS.

What's wrong w/ Megaman Legends, Rygar The Legendary Adventure and Castlevania: LOD?

But to your primary question: I'd love to see something in 2D (on Wii!) but there's somewhere near-zero chance of that.

 the first megaman in 3d (megaman 64) was a disaster and castlevania has always been better in 2-d.

3D action/adventure title for sure. Could end up rivalling Zelda if done right. Can't think of a Nintendo franchise which has made a bad 2D-3D transition. It would be amazing if it was Retro working on Kid Icarus - just look at how they transformed Metroid.