Hardly weeks after the initial release and availability, people have already begin tinkering with and modifying the new nForce 550 and 570 non-SLI chipsets, enabling them to work with SLI modes. “Magic-Pro” as they are called has a board that has a 550 chipset with SLI enabled, model “A2N5”. As unknown as Magic-Pro might be, it's definitely an interesting achievement and one worthy of a deeper look. Enthusiasts who love getting the most out of hardware will no doubt be trying this themselves. On more available boards, it seems both the chipset and the motherboard BIOS have SLI disabled, meaning that even after a successful mod SLI may not work.
According to the article, performance between modified SLI boards and standard SLI boards is no different, leaving plenty of speculation as to whether nVidia will let this sit or do something about it that further locks down SLI mode. This is akin to the days when an Athlon could be unlocked with conductive tape, and companies will often work to prevent users from doing this for various reasons (including illegal relabeling of products). Either way, it's a cool mod.