An odd subject name for this thread got me curious so i clicked to have a peek... sad to read what seems like a squable.
NVidia created SLI and licenses the feature to motherboard manufacturers. Unfortunately it's rather difficult to find 'real' information on how SLI is licensed. However sparse information exists and it seems it's a per motherboard change for motherboards where gaming cards are used ($5 in 2008). Unfortunately i've not found any information on licensing for SLI on motherboards where workstation card are used. The nearest i've found related to NVidia Quadro SLI is from NVidia itself and it only indicates mobo/card compatability specifically for Quadro card based workstations.
Not surprisingly, articles on SLI always seem specific to either gaming (GeForce) or workstation (Quadro) cards. I have never read an article that discussed Quadro and gaming card SLI interchangably on the same motherboard. That being the case, one can therefore not assume that where Quadro SLI works on a HP workstation, gaming card SLI will also work on that same worksation (as we simply don't know how it's licensed).
And thus @erico posting a link to a review that only mentions workstation based cards (and x58 chipset) does not fully answer the OP's question as the OP has not really indicated what graphics card they inetnd to use (gaming or workstation).
As such @Mtothaj comment is useful as it raises the issue for discussion. Pity erico resorting to defending his post and calling 'troll'.
I think a discussion on SLI motherboard capability verses gaming and worksation cards and drivers as related to license restrictions (if any) is the way forward... name calling is not... 
Pity NVidia emplyees with some real knowledge on the issue don't lerk here 
[edited to add]
As a final note, my Z210 has no issue with two quadro cards installed (Q200 & Q600) but the NVidia control panel shows SLI as disabled for both cards and there are not other SLI options i can set. Obvioulsy i'm using Quadro drivers.
Does this mean my mobo is not SLI capable or one or both grahics cards are not SLI capable (rhetorical) ? 