If you're still interested in realtime voxel landscapes, I'd suggest checking out this series of articles from (sadly now defunct) flipcode: http://flipcode.com/archives/Realtime_Voxel_Landscape_Engine...

This looks like the basis for an extremely cool Minecraft mod.

Beautiful, and if you didn't try the WebGL "DEMO" go back and try it.

I like the way the original faces map 1:1 onto the original mesh, too ... which would be important for a Minecraft-like environment with many block types, rather than the binary one discussed.

The Reddit discussion linked to this video of an engine using Elastic Surface Nets. http://www.youtube.com/watch?v=Rc1ztktWxJs

That was really interesting. I had no idea there were better approaches than marching cubes.

Great application of WebGL.