I don't even have a special maemo 5 package, it is all maemo 4.1.2.
The port largely consists of remapping keys so I am able to make it work for the N800 and N900 even though I don't have them because the N800 is mostly just an N810 without a keyboard and the N900 is like an N810 with maemo 5 and different keys (which runs Maemo 4 packages)

It might just work the same way N900 just works. If it doesn't there is nothing more I can do without having an N9 (I don't plan on buying one for myself)