Following the earlier photo leakage, the French manufacturer decided to officially unveil the 2011 Peugeot 508 GT and SW.
Propulsion for the 2011 Peugeot 508 GT and SW will be enabled by the company’s HYbrid 4 technology which will provide 200 BHP to the car’s all-wheel drive system while CO2 emissions level will be of just 99 g/Km. 
As far as dimensions the 2011 Peugeot 508 GT is 4.79 m long while the SW’s length is 4.81 m. Public debut will take place in October at the Paris Motor Show and at this point we do not have more details regarding performance and dynamic abilities.
The 2011 Peugeot 508 GT and SW price will also get announced at a later date. 
Peugeot press release :
The Peugeot 508 introduces the Marque’s new design look which has
evolved from the stylistic codes first unveiled on the SR1 Concept Car.
Combining both a stylish and strong design with cutting-edge
technology; quality, purity and efficiency have been the watchwords that
have guided the Peugeot designers and engineers during the creation of
the 508.
The stylish exterior design is elegant and timeless and full of
‘French chic’, equally at home in Paris or London.  The interior of the
car combines hi-tech with the use of high quality materials and every
detail has been chosen to offer indisputable perceived quality, both
visually and to the touch. An exceptional interior space, a very
generous boot, and a level of standard specification provide interior
comfort and convenience of a very high level.
In line with Peugeot’s strategy to produce vehicles that emit low
levels of CO2 and optimise fuel efficiency, the 508 has been
designed to optimise the performance of its engines, enhance
environmental efficiency, reduce weight and improve aerodynamics,
matched at all times to a broad range of highly efficient engines.
The Peugeot 508 will be powered by a range of engines all well
positioned in their categories in terms of performance and driveability,
but also fuel consumption and CO2 emissions.  All engines
will benefit from the latest engine technology including Peugeot’s new
e-HDi stop and start system. This is the first of the new generation of
stop and start systems which offers improved driveability and economy
enhancements of up to 15%.
After launch, Peugeot’s HYbrid4 technology will become available on
the 508 and will provide 200bhp performance with all-wheel drive and
emissions of 99g/km of CO2 or zero in electric mode.
The Peugeot 508 will be available in two body styles: a Saloon (with a
length of 4.79 m) and a SW (4.81 m).  Both models will be revealed to
the public in October at the Paris Motor Show, and will go on sale at
the beginning of 2011.
Utilising the PSA Group’s platform 3, the 508 will be produced in
Rennes in France, for the European market and in 2011 in China, for the
Chinese market.

Source: Peugeot