That of course only applies to Maemo, fully free systems like Debian or SHR don't have this problem and can safely be preinstalled on your device if you wish so

Makes sense.
It should be much easier without the double-whammy of the built in impediments and barricades in either the n900 hardware or the fremantle platform. And yeah without such handcuffs it should be able to do whatever the openmoko's can do....Yea...I love fremantle...but ....there are alot of distros I want to play with on my neo once it's in my hands...
Hehe...I know I for 1 wouldn't mind seeing proper Mer having a shot at the neo...bet it would do better and go further than on any other device it was tried on...(Not that I'm trying to necro a ghost...but I loved it on my n8x0's )

We even pondered to offer uSD with free OS for Neo900 on them. So you could swap uSD and voila: new OS. Like with every decent proud live OS, there may be an "app" that installs the OS to the Neo900 internal storage. Even multiple OS on one uSD are entirely possible. However our "primary OS" that we actually ship with the device, on internal storage, will most likely be the BSP package that we also use and that also allows you to do the factory tests to verify all subsystems and peripherals of Neo900 to be functional. A OS installer/selector should probably be part of this genuine OS, so users can chose/config which OS to boot from which storage location. Such installer may also offer download of OS images and setup, resp support user in the process of installing maemo fremantle to the device and then install the Neo900 compatibility adaption bits over it.
[edit] I figure such - let's name it NeoBSP OS - firmware would boot up in two different modes, maybe depending on whether it's first boot / batterycover closed / R&D-mode flag set / whatever:
A) The mode we use in factory would be the automated testing of all parts of the Neo900.
B) The mode that user usually would face when booting his new device will probably have to consist of:

1. a welcome screen,
2. some demo of the more interesting aspects of Neo900 (similar to a subset of what the factory mode does, but with much more interactivity and eye candy, showing compass, multitouch, etc),
3. and finally a text explaining the productive OS situation/concept (what's readily available in internet, from sites like debian, firefox, ubuntu, SHR, etc), a detailled explanation about the procedure to get and install maemo fremantle, and
4. a menu to chose one of those OS installation options from, or jump to the true factory test if user wants to, or a configurator for uBoot to boot up from an alternative volume on eMMC or uSD

/j

That would be a very good idea ...
out-of-the-box-start-up-and-run
Anything that makes initial 1st use as comfortable as possible...