I don't have AA or AF on and a few other settings like dynamic lights. But all the basic settings are toggled high like models etc.. Furthermore, those sites have a bunch of carriers and units on the screen to stress it. I obviously didn't go to great length to test my system like that. I just know my system totally handles SC2 even with big 2v2 battles.
Also, a quote taken from the first article:
"According to the Windows 7 Task Manager the Starcraft 2 Beta utilizes only two cores and our benchmarks confirm this: The Intel quad-core Q6600 is only slightly faster than its dual-core sibling, the E6600. But Starcarft 2 reacts very well to additional cache - especially the E8400 and the two Lynnfield CPUs benefit from that while it is a disadvantage for the Athlon II X2 250"
Quad core isn't utilized in SC2 so big systems aren't going to obliterate my E8400 @ 3.5ghz.