According to the 10 hours of research I've done on Nehalem (sigh...

), it turns out after all that it will offer a 30-40% overall performance increase over Penryn.
I was very skeptical, until this quote confirmed my choice:
"What Intel did to AMD in 2006, it is doing to itself in 2008."
And as of today, now that we've seen Nvidia's PhysX drivers are so CPU dependent, it might not be such a bad idea if you know what I mean.
http://www.fudzilla.com/index.php?option=com_content&task=view&id=8859&Itemid=1