This should help reduce bandwidth competition on the system ram by about 10 percent. I think intel integrated graphics don't overclock well at all because ddr3 has a tenth the bandwidth of gddr5, AND it has to share with the cpu.. and whenever anyone does ram benchmarks, they use cpu tasks and not gpu tasks. It seems anything over ddr3 1600 is basically a waste for cpu tasks.. but i bet graphics takes everything it can possibly get. If Haswell has a soldered IHS, it should be the best overclocker yet, because you only need a single closed loop water cooler for your whole system.
Weird that Archlinux wasn't mentioned, being as AUR has a bunch of x32 packages and if i remember correctly, Arch has x32 enabled in the default kernel, as well. (even though Archlinux doesn't 'officially' package and support x32 - there are still people using it, for sure).
...and in Archlinux' case 'packages haven't just begun to surface' - they have been flowing in for quite a while, with AUR having well over 100 packages with x32 support;