I have never understood the power of petitions.. no matter how many people add themselves to this petition will that make a difference? Will google change its mind if a 300 odd (or even 3000 or even 30000) people add themselves to this?
They know a small but loyal following uses wave. They are shutting down because that wasn't what they had in mind for wave. They were aiming big and failed. That's ok, but only if it doesn't continue to drain from the company.