No SLI will not be a requirement just to play games, but it will be one of the options for playing the top games at the highest settings. While right now it is pretty useless to have 2 vid cards in SLI, the same can be said for Dual Core processors. Actually its more true for the processors, since there is no consumer software currently out that supports mult processors, so you see no difference in performance over single core processors. But someday there will be software that utilizes their potential. The same thing can be said for SLI, but atleast for the moment you still see that 30-35% gain, instead of none.