http://www.staralliance.com/en/press...ralliance.html
In a nutshell:
With "new" Varig having been granted its operator's certificate (CHETA), "old" Varig no longer meets the conditions to be a member of Star Alliance.
The press release does not indicate whether "new" Varig is expected to join but it states that *A wants to increase presence in South America:
“Star Alliance continues to offer the most intercontinental flights serving more cities in Brazil than any other alliance and will continue to expand its services in this important and growing aviation market”