Sorry, I only found pages in Portuguese
The first cities will be São Paulo, Belo Horizonte (where the Brazilian Googleplex is located) and *drum rolls* RIO DE JANEIRO!!!
I'm very eager to see it, and maybe appear on the net with my face blurred.
It will be sponsored by FIAT, the StreetView cars here will be red Fiat Stilos:
Edit: here is the official YouTube channel http://www.youtube.com/streetviewbyfiat