I concur with the pandora assessment.
Fact is the pandora is exactly that...a retro gaming device that runs some linux distros. Amazing device...yup. (Was thinking of getting one...but am now waiting for the Pyra...and then I'll prob throw money down then when ordering commences.)
There is a huge difference tho between the neo900 and the pandora/pyra
...the neo is far more compact/ portable...it's phone function, the utilization of running alt distros properly, and the fact that Freemantle os will have at it's fingertips the depth, diversity and scope of the years of design and development of n900's Fremantle (and possibly...potentially... modified Chinook/Diablo Harmattan...etc..) maemo applications and programs make that a different kind of beast to the pandora and I believe a different set of circumstances and foreseeable outcomes concerning sales and possible "orphaned" devices. A more on-par example to the neo would be the gta04... No "orphaned" devices available there.
Joerg can answer more clearly how the device donations are fathomed and understood and applied to production and how possible "leftover/ unclaimed/ orphaned/ unwanted" devices will be dealt with.

Concerning these topics
A- I simply have been running with what I understand to be the process.
B- What I have wished/ done with my own donations/ deposits,
C- Logically extrapolated various outcomes.
So ...yeah...a wee bit o' supposition on my part...
pretty much a...wait and see...and get more deets... kinda sitch