Interesting conversation in the Sansar Reddit group titled, appropriately enough, "Share Your Experience", which like anything on Reddit, deserves a grain of salt. But from my quick read, the basic gist is Sansar seriously seems like Blue Mars, a virtual world with extremely high-end graphics launched 6-8 years ago which I did some consulting for back around 2010. For instance, someone in the /Sansar group writes:
"Just like the SL client, if you want access to Sansar you'll use the Sansar client. The difference is there is no 'mainland'. Regions aren't connected. Going from one place to the other means you exit and load up a new 'experience'."
Which seems a lot like the Blue Mars client (see above, and here), which first launched as PC-only and wasn't a contiguous world. Like I said, grain of salt in all this before anything's announced, but Linden Lab staff have suggested this very kind of interface and experience during Sansar previews. (Sansar is also first launching as a PC-only product, with Mac and mobile said to come later.)
The comparison isn't necessarily a bad one, by the way -- Blue Mars had a lot of great ideas and ambition, especially for third party developers, which was why I wanted to help launch them:
I think Blue Mars could have been a lot bigger with better market timing -- but the thing is, the market for PC-centric, 3D online worlds with high-end graphics is still about the same size now as it was in 2010 (i.e. not very big)... and back then, we weren't pushing Blue Mars as a VR-centric product.