The website of the Diario Catarinense, from Port Alegre, the state capital of Rio Grande Do Sul, said that 742 biometric machines had been installed in the city, and only three removed from service due to problems, or around 0.4 percent. An official at the TSE said the machines should be rolled out to the whole nation in 2014.
Among English language media outlets, this topic seems to have generated interest in the Chinese press and not elsewhere.
I tried without success to chase down the Porto Alegre article for any Portuguese speakers out there. If any readers happen across it, I'll certainly post a link.
UPDATE:
This may be the article referenced by Xinhua:
Eleitores do município de Canoas (RS) aprovam urna biométrica
Nely Menetrier, 84 anos, também se mostrou satisfeita com a urna biométrica.Translation:
– Gostei da nova urna, foi fácil e rápido.
84 year-old Nely Menetrier also expressed satisfaction with the biometric ballot box. "I liked the new ballot box; it was easy and fast."
Voting is compulsory in Brazil so technologies that make the process more manageable will have a large impact. It wouldn't shock me if more votes are cast in Brazil than any other country.