I think its important to recognise that there is already a Free and
Open Source community within Second Life. And there is certainly a
Free Culture environment, with the Creative Commons organisation
active within SL organising talks etc. So in a way they are already
part of our community.
Even if SL eventually falls in a heap (there is certainly no guarantee
that SL is the future of a 3D internet), or the servers never get open
sourced, I think an open source 3D user driven environment much like
it is pretty much inevitable. And the community will learn a lot in SL
about what works well and what doesn't in a virtual 3D environment,
and this knowledge and experience will transfer well to whatever
eventually does emerge.