From what he [Yoz Linden] said, it sounds like Linden will continue to host the presence, search, and currency/payment services (or at least the default, global instances). As part of this effort they are apparently paying attention to emerging standards for cross-world portabilty of avatars.
I suspect the “grid of grids” comment by Linden Lab’s Joe Miller actually refers to an effort begun with Wells Fargo. Recall that the issue with Stagecoach Island was that while it was only accessible via the Wells Fargo website, the island itself was actually still part of the Second Life grid. That’s almost certainly how the Second Life developer content Swivel used was moved from the Main Grid over to Stagecoach Island. It’s also how a few clever folks found holes in Linden Lab’s effort to isolate it from the grid (reLink).
So while “grid of grids” was probably an older, separate effort, that doesn’t mean it won’t play nicely with the current LiberaciÃ³n project.
The bigger question in my mind is: what is the LiberaciÃ³n project’s ultimate goal? Is it to develop an avatar portability standard… perhaps with an eye to teaming up with Microsoft for an XBox cross-over (reLink)? Or is the endgame a fully open source application with Linden Lab as stewards of the avatar portability protocol while they upgrade their private, non-open source server system (SL3) which they then make available to customers to whom they provide hosting services?