angelscape

Not entirely. The RSPS I used to play along with this actually had 7 worlds. (Like Runescape). It had World 1, World 2, World 3, Classic 1, Classic 2, Classic 3 and Small Beta.

Of course, it would mean 2 different clients since they'll both be based on different sources, different custom items, different base and all.

But, that server had people donating money like crazy. And it had 3000+ people on nearly all the time...