I have an N810
I also would like to see Mer fully functional
I'm willing to contribute however I'm needed. I can code, test, cross-compile, whatever.
Hopefully, Mer can be done in such a way that newer N900 apps could be run on these older devices with a simple re-compile (due to CPU, no way around this I don't think.) -- Maybe, one day, we might be able to automate something to traverse the Fremantle/Hermattan repo's and automatically cross-compile software for mer... I know - I'm dreaming

I personally plan to be upgrading to an N900.. so it won't benefit me too terribly... but I am more than willing to help if I'm needed keep these devices useful for their Fans.