I've been wondering if we can add repo's from other devices..
(ARM Linux based)

Maybe things like the Pandora (we will need to port libpnd to use .PND files) and smartQ v5/7. There is a cortex based smartq (or similar to smartq).

The N900 IMO is limited by the maemo repo's... I have added qoles (for bootmenu).

Things like the iPh/od have many, many, many repo's which can be added to cydia to extend it even more....