They ofter change the motherboard if a cheaper substitute is found that meets the specs of the published specs. So while the model you have to dissect had that board what keeps them from changing it?
To the CNET editors:
"Even though Asus has taken a lean-and-mean approach to gaming performance, it doesn't quite provide the larger picture upgrade path of the Dell system, which is already fairly limited. Neither desktop is SLI or Crossfire capable, so adding a second graphics card it out."
This is not true. The Essentio CG5290-BP007 uses the ASUS Rampage II GENE Republic of Gamers motherboard (http://reviews.cnet.com/motherboards/asus-rampage-ii-gene/4507-3049_7-33542739.html?tag=mncol;psum). It has two PCI-E X16 slots with both CrossFireX and SLI support. all you need to do is buy a second video card and a more powerful power supply and you're all set.