Originally Posted by GrouchyAdmin

It's honestly not that different; just some core routines are replaced with 64 bit counterparts which is a fuoll register size on the current CPUs. Even if you had a 64 bit line and had to split it across two, it's no big fucking deal, since we're no longer dealing in single Mhz.

Unless you really, really, really, really need more than 3.2GB of RAM for OS+Application, there's virtually no need to adopt at this time; time_t will hold on for a couple more decades.