I agree, Maemo would benefit from rolling out updates to independent subsystems when they are independently ready.

But you know, a lot of subsystems aren't completely independent - even ones which seem like they should be - and then it's a good idea to do lots of testing of them together.

Especially for a complex device sold to people who aren't expecting to deal with "computer problems" and possibly sold in the millions.

For the most part, Ubuntu (et al) roll out applications updates independently, but core subsystem updates are more carefully tested, and they are not usually rolled out until enough time has been spent testing. It is the same with Maemo: Application updates from maemo.org and (one day!) Ovi will roll out independently.

I think the main thing missing from the Maemo picture is there is no easy way for people who are prepared to take risks to download the firmware or firmware components being tested.

But then, Nokia has more to lose than Ubuntu if lots of people's devices are bricked, vs. Ubuntu not booting and needing to simply go back a kernel version in the bootloader.