With the 32-bit architecture falling behind and becoming less and less prevalent, certain bits of software are bound to drop support for it eventually. This is what the Dolphin Emulator team did today, by dropping support for the 32-bit builds. It's not just because 32-bit is becoming less common, however; part of the reasoning behind this decision was that the latest Microsoft Visual Studio Compiler doesn't support Windows XP. Unfortunately for XP, he's the last sibling of the Windows family to be primarily 32-bit, while his younger brothers Vista, 7 and 8 are designed for 64-bit. Along with 32-bits based processors dying out and 64-bit ones becoming more and more prevalent (since 2003, in fact), every day there are more reasons to leave 32-bit behind. Source Discussion on Dolphin Emulator forums Considering that 32-bit machines really weren't powerful enough to run Dolphin at a playable rate and that only 7.8% of the downloads for last April/May were 32-bit Windows, I say that this isn't a bad move if it allows them to spend more time perfecting the 64-bit build.