It seems as if the people still running Windows XP for gaming are slowly being phased out as more and more games are requiring DX10 at the base level, and it would seem as if Battlefield 3 will be no exception to that growing trend.
A rendering architect for DICE by the name of Johan Andersson, tweeted earlier;
Frostbite 2 is primarily developed for DX11. XP & DX9 is _not_ supported, 64-bit OS is recommended. Lots of time to upgrade if you havent!
Of course the typical rage ensued, with people all over defending Windows XP and fighting for it’s relevance. One thing’s clear, DirectX 9 wont be supported forever. So if you haven’t yet, make the jump for Windows 7, it’s a great OS and DICE seems to agree.