The article mentions that it could be a reference to High Fidelity, Philip Rosedale's new project. However, it couldn't be that, because Hi Fidelity is totally open source, and the article also mentions that this world will be closed source.
SL could be using High Fidelity code (it's permissively licensed), we can't tell. But yeah, I assume these are separate things. There are lots of next-gen virtual worlds platforms, 1 or 2 more is not that surprising.
