They're adding new servers because they're hoping the PS4 launch and Steam launch will bring in enough new players to be worth expanding, but none of the servers are platform specific. All servers will be available through all platforms, just as they are now.

The only special rule for the new servers is a temporary one — that character transfers to the new servers won't be allowed until after the economies on those servers have time to mature a bit. So you won't immediately be able to move an existing character to one of the new servers, but you can create new characters there if you want, regardless of what platform you're playing on.