Ohhh, I want one. I know the US version of the QR25 under went some revisions as well as the VQ35. I'm still waiting for the electronic Field Service Manuals to come out so I can check the specs and see what has changed. If the crankshaft is fully counter balanced with the revision (to allow for the higher redline) Spec V's are going to finally get the nuts they deserve.

I lifted this from Fresh Alloy's web site:
The 4-cylinder QR25DE and the V6 VQ35DE engines both have seen extensive revisions for the 2007 model year. The VQ is now in its fourth generation, with added features such as a new twin induction system, reduced friction, improved cylinder head cooling, and twin knock sensors. Nissan expects the VQ-powered Altimas to be capable of 265-plus horsepower and 255ft-lbs of torque. The QR engine now features a larger intake and increased compression ratio (9.6:1 vs. 9.5:1). The end-result is a more refined engine with 165-plus horsepower and 170-plus ft-lbs. A new dual exhaust system reduces backpressure by 35% on the QR and 50% on the VQ.

It's also rumored the cam profile is more aggresive, maybe more so than the ones that are available now.