The biggest problem still remains that Audiosurf uses Quest3D and that is only available for Windows.
Dylan (the developer) has suggested he is creating a new engine that would be multi-platform (at least, Windows, Mac and Linux) in the past, but has then gone silent on the matter so the community has no idea where that stands.
Without this development, porting to any other platform is impossible.
There is a much simplified port to the Zune HD that is free (but ad-supported) if you live in a country where those are available.
Smartphones do have the processing power, but would again require this engine rewrite, unless the Zune version were ported which may or may not be a simple task. Again the community doesn't know.
Also, the music analysis would need to be sped up and optimised, otherwise you could end up waiting as long for the track to be analysed as you play it on slower devices.
I think that pretty much summarises it.
We're in the dark.
