There will not be a V8. It had been a likely move with the new OHC V8 GM had in development for use in a lot of Cadillacs, but the push for better mileage by CAFE, etc. killed the engine before it was ever used.
But as linked, the 2009 Lambdas are supposedly getting the higher output Direct Injection 3.6L, AS WELL AS revised interior components centering on the center stack which should be the "new" integrated variety, which means buttons and such of the head unit and HVAC are integrated right into the main dashboard and not separate units sitting in there, as now.
That's the expectation, at least, based on information that is known.
The last order date for 2008's is mid April, and then 2009 order banks should be open in May. Information as to what the 2009's will have should be out in March sometime, when GM releases the ordering guides.