WiiWare World had posted up an interview with Tyrone Rodriguez of Nicalis, in which they talk mainly about the upcoming WiiWare version of Cave Story. Some excerpts:

Will Cave Story retail at a cheaper price point than the average 1000 Wii point game?

I can't promise anything, but we're trying to bring it in under 1,000 points. ($10 USD)

Has Pixel ever considered creating a Cave Story sequel? If so would he want to spend five years in developing it this time?

He's probably sick of me asking about a Cave Story sequel. For me, I just want to know what happened before or after the events of Cave Story. I wouldn't get too excited about the idea of a sequel, he's pretty content with what's going on with Cave Story on WiiWare. It's like a new game to him. I can't speak for Pixel, but I think if he were to do a sequel, he might be able to do it in much less time than five years. In that amount of time he made three versions of the game. He admitted to me that he feels like a much better designer now.

Do Nicalis have any current plans for other WiiWare games? Do you want to develop any original IP or find more highly esteemed freeware to port?

We do have plans for more WiiWare games. We haven't announced our next title, but you should hear about it sometime next year. Nicklas Nygren (known as Nifflas to his fans) is leading the design for this one. (source: clysm)

Nicalis Interview: Cave Story (WiiWare World)
Cave Story Art Comparison: Mimiga Village Tiles