The cost is one cent per minute which is practically free. The annoying part is that you can't forward to an "international number". Note that if you give people a web button, they can still call you for free. Even with the upgrade, grandcentral still appears to work so you can use it for a while until google voice gets more of the options you need.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...