You might want to wait for Rust to be ready, because this way you can build an OS that truly made for the future (very optimized for multi-core). If you don't

You might want to wait for Rust to be ready, because this way you can build an OS that truly made for the future (very optimized for multi-core). If you don't want to appeal to the general market, but more for a specialized market (like in enterprise or whatever), then you should probably optimize it for AMD's Mantle API, too, and take full advantage of the performance for both the CPU and GPU that you get from that. Also don't even bother with 32-bit.