That would depend on how retarded your distro is behaving (i.e. how many unneeded 32bit libs they install just for the fun of it).
In other words, you can have an *entirely* 64bit system and it works just fine. If you need to run some specific 32bit program, you install ONLY the required dependencies instead of *ALL* 32bit packages provided by the platform, which is what fatelf would do (in addition to installing ALL of the packages for ALL platforms that *aren't even compatible* -- like ARM, SPARC, PPC, PPC64, etc.).