Thought I'd have a look, just out of interest. I didn't expect what I found.
From all accounts(100+ websites, enter GM Zeta or just Zeta) the Zeta platform will not be used in any European car .
Opel were considering importing the VE Commodore but have decided against it. The Opel Insignia was canned before release. Opel have ruled out using the platform as it is considered too big for Europe.
SAAB is a no go until 2007/8 at least as they are currently researching building their car in China or Korea but are unsure if they will use the Zeta platform at all. SAABs are currently FWD.
Cadillacs are using the Sigma platform until 2008 and have not used the Zeta at all.
Chevrolet have used the platform only in three concept cars. The Camaro planned using the Zeta platform was canned but has been reinstated for release in 2008.
GM (North America) considers the Zeta to be far more expensive than originally planned and will use the Omega platform into 2007 at least.
The resurrection of Buick has been put on hold due to the above decision.
Interesting two hours of reading.
one link of many
http://www.autoweek.com/apps/pbcs.dll/article?AID=/20060116/FREE/60116001/1024/LATESTNEWS
GM revived its rwd plans late last summer after halting efforts to develop North American vehicles on Zeta last winter. Last winter, GM executives said that the initial plan for the Zeta vehicles was not workable but pledged to develop a new strategy.
Possible Zeta vehicles included the Buick Velite concept, Pontiac GTO and Impala.
Stefanyshyn would not reveal the entire lineup under consideration but said the next-generation Impala "is a possibility."
GM's styling studio has prepared both rear- and front-drive versions of the next Impala, according to an industry source who did not want to be identified.
The engineering of the new group of vehicles will be handled by GM's Holden subsidiary in Australia, which built the Holden Monaro that is the basis for the current Pontiac GTO.
The architecture will debut in the second half of this year on a redesigned Holden model. GM also is considering a rwd model for China.
Ok one more:
http://www.channel4.com/4car/news/news-story.jsp?news_id=14076&ref=archive