I actually don't care whether Sailfish OS will be available on N9 (and not because I don't own one).
The question is deeper. Sailfish is Mer + some parts of Nemo + Jolla UI.
So for sure we know that two parts of it are free software. Therefore we can port it even to different architecture, not only N9. The question is whether Jolla UI part is free software? Alien Dalvik definitely is not, so you cannot run Android apps on other devices unless you implement your own Dalvik port.
So it is necessary to define "hack", what does it mean, that experienced hacker can port it? Does it mean that he can take binary build and force it to run on a different device, or does it mean he can adapt this software to run on a different device by hacking the source.
For me, the first way is not acceptable, i. e. I wouldn't use such a port to N9, and I would prefer to run Nemo. By running it I would know I contribute to it's development, even by reporting bugs, and by asking people to port some FLOSS to it.