I have started exploring the OSgrid and I find that it starts to look like SL. Really great builds, bad builds and ordinary areas. Some of the sims are not available but many in the core are and you can travel around and find more and more great builds.
And there are many former Second life builds that show up on the OSgrid. It is cheaper and you have a full sim to build on. You can realize many more ideas.
And the hypergrid idea is good, to visit several grids and that way get more people on all grids.
What is needed now is a way to rent out space on Opensim grids making them more commercial and some actors that take copyright issues serious so you can trust them to put your stuff on their grid. Or a way for Opensim to get objects from other trusted servers where you can rent some space for the things you create so they never leave to get copied every where.
I think it is important that you own your avatar and things you create.
I see good things in the future for all the grids out there.