OCW has posted an article on the NVidia Forceware 81.82 drivers
What is new in 81.82 ? Well, would it be something that is as special as what we brought to you before in ver 77.77, SLI without bridge. Well, you can think along that line. Version 81.82 brings more surprises as it not only add in new game titles, bug fixes, it also incorporate what its competitor have. That is, you can now use different branded cards (of the same core) and run them in tandem.NVidia Forceware 81.82 supports SLi using cards made by different manufacturers
What does that mean ? Basically, it means that you already own a XXX brand, you can now upgrade to SLI by purchasing a YYY brand and plug in the SLI bridge. Everything will work perfectly. This was not possible in previous versions (as far as I know, unless you flash the same firmware into both cards).