Yep, but the point is about running real Debian, not any Debian-derived distributions like Raspbian that have been rebuilt for ARMv6.

With the old Pi it was not possible because the CPU only supported the ARMv6 instruction set, while mainstream distributions (Debian, Ubuntu, Fedora, etc.) all require ARMv7.

Fortunately the just released Pi 2 sports Cortex-A7 Cores which use the ARMv7 instruction set, which made this possible without any full rebuild.

It would have been possible to use Debian, but the armel build which is running on ARMv6 would have diminished the performance even further, as it servers for very old ARM processors.