RMC of GoNintendo did an interview with the company and Pixel, and here's the important bits:
-----
RMC: How involved in the project is Pixel?

TR: He’s extremely integral to the project. Cave Story is his his idea, his design and his game. I wouldn’t feel comfortable at all bringing the game to Wii if it didn’t have his blessing. Obviously it does, but more importantly he’s deeply involved with the process. We run pretty much everything by him. In fact, I’m going to see him in a week so we can meet about a few things.

RMC: Is the gameplay going to be significantly changed from the original?

TR: I love the game as-is and I think the general consensus is the same. So, to answer your question, there are no significant changes in gameplay from the original.

RMC: What can we look forward to as far as music? Will the old songs be retained, or will there be something else?

TR: The WiiWare version of Cave Story features all-new music rearranged by Yann van der Cruyssen. He’s worked with Nicklas (Nygren) in the past and we’ve really liked working with him. We’ve paid very close attention to stay as faithful as possible to the original music. Each track is passed off while in-progress state to Amaya so that he can review and approve it.

Yes, the old music and graphics will both be retained via a switch. You’ll also be able to mix-and-match audio and visuals. So, if you like the old art and new music, or vice versa, you can do it. Cave Story has a huge fanbase, we’re aware of that and want to make sure that it’s true to what they expect and Pixel-approved. If they don’t like the new art or music, we won’t be offended and they can play the game in its original state.
----------
The rest of the interview with some other juicy details can be seen here: http://gonintendo.com/?p=58250

Also, if you checked out the site a little more, they linked the IGN videos and said that yes, the sound and music is still very much a work in progress, so nothing we've seen is final.

And for closing, Pixel on the site himself thanked Aeon Genesis for the translation...I don't know if he contacted Gideon or anything, but they're using it.

____________________
Layout by Kattwah