It's official, the President signed a decree that includes Bahia in summer time. I did not find the decree yet but I am convinced now that the news reports the position of the president.
I found nothing oficial about the 32 municipalities in Mato Grosso, I'm still looking and update when I find the decree.

link whith the news:http://g1.globo.com/bahia/noticia/2011/10/dilma-assina-decreto-que-inclui-bahia-no-horario-de-verao.html

Gwillim, thanks for the translation below.

Guilherme

On Mon, Oct 10, 2011 at 12:35 AM, Gwillim Law <gwillim@gmail.com> wrote:
In case anyone needs a translation of these messages, here is my effort:

From Zulmira:

Dear Guilherme,

In accordance with Decree 6558 of Sept. 8, 2008, summer time [HV = horario de verão = DST] will take effect from 0:00 on Oct. 16, until 0:00 on Feb. 26, 2012. The states which will enter into summer time are RS, SC, PR, SP, RJ, ES, MG, MT, MS, and DF [Rio Grande do Sul, Santa Catarina, Paraná, São Paulo, Rio de Janeiro, Espírito Santo, Minas Gerais, Mato Grosso, Mato Grosso do Sul, Distrito Federal].

Thus, BA [Bahia] will not have summer time. I should clarify that summer time depends on a Federal Decree.

Courteously
Zulmira Brandão
Time Service Division

Guilherme's original message:

Good day, Zulmira,

I would like to confirm whether Bahia will have summer time this year?
I would also like to know whether this depends on a federal decree?
If the answer to both questions is yes, what is the specific decree in this case?

Thank you,

Guilherme Bernardes Rodrigues


2011/10/7 Guilherme Bernardes Rodrigues <oguilherme@gmail.com>
Robert, 
   About the change in Bahia, Brazil [...]
follows the e-mail exchanged in Portuguese

---------- Forwarded message ----------
From: <zab@on.br>
Date: 2011/10/7
Subject: Re: Horário de Verão na Bahia
To: Guilherme Bernardes Rodrigues <oguilherme@gmail.com>


Prezado Guilherme
De acordo com o Decreto 6558 de 08 de setembro de 2008 entrará em vigor a partir da zero hora do dia 16 de outubro, até a zero hora do dia 26 de fevereiro de 2012 o HV. Os estados que entraram no HV serão RS; SC; PR; SP; RJ; ES; MG; MT; MS e DF.
Portanto a BA não terá HV. Devo esclarecer que o HV depende de Decreto Federal.

Atenciosamente
Zulmira Brandão
Divisão Serviço da Hora


Quoting Guilherme Bernardes Rodrigues <oguilherme@gmail.com>:

Bom dia Zulmira,
  Gostaria de confirmar, este ano a bahia terá horário de verão?
  Gostaria também de saber se isso não depende de um decreto federal?
  Se sim para as duas perguntas qual é o decreto a respeito disso.

Obrigado,

Guilherme Bernardes Rodrigues