Nokia will not be releasing Maemo 5 for the 770, N800, or N810, correct. Some folks in the community started the Mer project because they felt Maemo could be redesigned and rebuilt in a better, more open way. This happened well before Nokia announced Fremantle and its lack of support for older hardware. So, continued support for old hardware is benefit, but wasn't the impetus. Nokia has made no announcements regarding Maemo 6 for Maemo 5 devices. At this time, it appears unlikely that Maemo 6 devices will bring the same sort of performance leap as is keeping Maemo 5 from older devices, so it seems probable Maemo 5 devices will be upgradable to Maemo 6. No one is promising anything though. As explained above Mer isn't "Fremantle for older devices". Mer is another OS, compatible with, and developed alongside, Maemo, but in a more open way. Currently, Mer targets Fremantle technologies, but as Nokia releases details of what Harmattan will bring, Mer development will adjust to match it.