They could probably make it an entirely animated show like Star wars: The Clone wars as a short series, But that has alot of issues with it. I don't see it happening though, due to the fact that it's a "children's" sci-fi book from the 90's that only we seem care about anymore. Plus the issue of what network would play it because Nick already had a show for it, there might be legal problems behind it being used by a different network. (This type of show wouldn't fit the style of modern day Nickelodeon).
I don't like the idea of it becoming a movie. There's just too many crucial points that would be left out of a 2 hour movie, and no one would like it. Also, movies always ruin everything and start a bunch hype with new "fans" that we would all rather not be associated with.
Personally, I think an extremely well done fan-made animation would be enough for me. Assuming it was done convincingly, and it captured the story/charactors accurately. If i was good enough with that sort of thing I'd do it myself.