Yeah, I've heard Roocke drops in the older 3.4L carrera engines into boxsters. Its looks like a sweet setup. I think the 3.4's have 295hp stock. That should change the personnality of the boxster a tad.
I think the swap costs big bucks unfortunately. If I had a regular boxster, I would probabbly eventually do the swap since the hp differnce between the 2.7L and the 3.4L is quite big. Since the difference is less dramatic with the boxster S, it would be less of a bargain. I'd probabbly keep the 3.2L on the S and put bolt-on mods on it. You would get about the same hp as the 3.4L but save some cash I'm sure. If you want to see some quality mods IMO, go to
www.fabspeed.com Vicelike . They have headers,exhausts, intakes, and they do in-house dynoing to remapp the ecu. Their boxster package that includes all these things adds a claimed 34hp to the wheels. So that is right around 40hp at the crank. They also have an exhaust bolted on a 996 that sounds outright badass. It is fierce, as well as a boxster video clip.