As far as development for the client goes, you can follow this thread for details of issues and such that are documented:
http://www.eqemulator.net/forums/showthread.php?t=27429
If you are referring to empty new zones and meaning the zones that replaced the old versions, the answer is that the server still sees the zones as the old version. If you want to use the old version, you could still copy the old files from a Titanium client into your SoF folder. If you want to use the new versions, I think other than the freeport zones, you would need to wait for Azone to be updated so we can generate new .map files for the new zones. Otherwise, you can't cast on targets and mobs won't aggro even if they are KoS unless you actually hit them (because they can't see you - no LoS). If new .map files could be generated, you could then just remove the pathing grids, and use #spawnfix to fix spawn locations, since they would all be wrong for the new zone versions. Then, you would need to redo the pathing from scratch and also add in doors and objects manually.
None of the zones later than Titanium have been populated in the PEQ database, so all SoF zones are empty unless you populate them yourself for now. Andrew80k has been doing some work on getting the EQLive packet collector tools working again, though. Once he gets that done, people can start collecting data from the new zones, and that will make populating all of the new zones MUCH easier and faster. Until those tools are working, the new SoF content is probably more for custom servers than anything, since we can put whatever we want in them without having to try to mimic live. If you want to see a couple of the new SoF zones populated with custom content, you can check out the 2 we have open on Storm Haven. Just create a new character while using the SoF client and you will start in Crescent Reach. And from there, you can zone to Takish Ruins, which is the zone I am currently working on and is coming along nicely.