You can't :( - Ahsan Ali

The best you can do is trash it or mute it - Ahsan Ali

Trash it (it mutes it and hide it from your Waves). Emptying trash (not yet available) will probably remove yourself from the Wave. - Jérôme

Thanks! How do I trash a wave? ;-) - Rubin Sfadj

Oh, I see... You can only trash a wave by dragging it into the trash can, and drag and drop requires Gears, which isn't compatible with Safari in Snow Leopard yet. Fantastic. - Rubin Sfadj

You can use the "Trash" button (which you'll see when you expand the wave window) - Ahsan Ali

Silly me ;-) - Rubin Sfadj

They mentioned this issue in this week in google and they said they're fixing it.. coming in a few a weeks apparently - Jay

Interesting. The more I toy around with Wave, the more I realize it's still at a very early dev stage. - Rubin Sfadj