I was wondering if any of the heavyweights around (Svartalf?) could enlighten me with this.

If one is going to distribute 64-bit linux binaries, the issue of where the dynamic linker is becomes, well, an issue. LD_ vars can't be used to set it.
Pure64 systems have it in /lib and multilib systems in /lib64, generally.

I was thinking it would need a wrapper script such as
[ -d /lib64 ] && /lib64/ld-linux-x86-64.so.2 $APP || $APP
What's the preferred way to solve this?