This is kind of a late update but here it is:
"Overworld available on Test Center"
"You have all been patiently awaiting the arrival of our Overworld build, but wait no longer! We've opened the gates to the Mythos Test Center and are giving all our adventurous testers access to the new Overworld."
for more information about this update go here:
Overworld available on Test Center | Mythos
"For those who do not know, the Overworld is a complete change of the way Uld is organized. No more instanced roads and crossroads, now the whole of each zone is a single area."-
Mythos Conclave