svdl,

     For me, the second core gave a speed boost of ~85% over a single core with high render settings. That's why I'm very curious for your tests when you have time. First, to see how the Intel scales 1 core vs. 2 and of course then to see how it scales 2 cores vs. 4. :)

     4 cores have other benefits beyond raw rendering time, I'm not at all trying to discount quad core as an option (I'm looking into it for my next upgrade personally). It will just be very helpful for all of us looking at quad core systems to see some actual numbers.

     I think the pivot point between cost/benefit of buying two dual core systems vs. a quad core system isn't necassarily settled, plus a quad core system get's bonus points for being more managable from a practical use standpoint for many people.