Does F-Secure Mac Protection Technology Preview work in Mac OS running in 64-bit mode?
No, but don’t worry – by default OS X boots in 32-bit mode. In order to get OS X into native 64-bit mode you need to do special tricks during the boot (e.g. holding down the numbers 6 and 4 on the keyboard while booting). If you have not done that, you are good to go. Mac Protection installer does not check the running kernel if it is running in 32-bit mode or not and will not function in 64-bit mode kernel.