As the title states; Will OS X 10.7 Lion be 64-bit only? Vote, and motivate your opinion. I personally think they will. If you look at the statistics from adium users, 95% of the users of adium has a 64-bit capable mac http://adium.im/sparkle/ (second graph from above). And all news mac sold the last 4 years are macs with a core2duo/xeon/core-i-series or other 64 bit capable processor. In the pas Apple has often used hardware features to decide if systems can or can't run a specific version of OS X; e.g. Snow Leopard, runs only on Intel macs. EDIT 28 feb 2011: I see there's a big discussion going on about this topic. What I meant to state is; Will Apple drop support for Mac's with 32-bit processors, with Lion? Because I think it's possible for Apple to reflash 32-bit EFI to 64-bit.