The latest engine bay shots of the 2009 CTS-V offer us a little more insight than we were able to glean previously. There's a clear shot back to the firewall, and the beefy strut brace is showing signs of revision. Moreover, from what's visible of the engine it appears that previous speculation of forced induction is so much chatter.
If we were to play GM-Overlord for a minute, it'd make the most sense to plop the Corvette Z07's LS7 into the CTS. You'd spend less on developing a super- or turbo-charging system, and reliability has been on a years-long field trial with the Z07. Spending less underhood means there'd be money left over for suspension development and interior fitment, both crucial areas where Cadillac needs to bring it. Throwback musclecars are fun for five minutes or so, and then they're just a handful when the road gets twisty. If the CTS-V is going to whip some foreign-accented hindquarters, it'd best be an excellent all around performer that needs no excuses when it comes to accomodations.