Right now, it would probably only be custom servers that are making use of the zones past Titanium. That is because we would need the packet collectors working to make them easy to fill in like Live, and also because PEQ is still a ways away from getting to Titanium+ expansions for their Database. My server, Storm Haven, has a couple of SoF zones in use so far for the leveling content I am working on. I just finished up the first 2 and am making an SoF server base for getting to the new SoF content that is in the works atm. Once the base is done, I will be starting on another leveling zone, but they do take quite a bit of work and time to complete each one. Also, when I say "SoF zones", I don't always mean that the zone comes from the actual Secrets of Faydwer expansion. I mean that it is a zone that is included with the SoF install that is not included with Titanium, so it can be any of the multiple expansions in SoF that are after the Titanium ones. So far, I have Crescent Reach, Ruins of Takish-Hiz, and the new SoF base is Temple of Marr (freeporttemple). The next leveling zone I am going to start will probably be Stone Hive.
I don't know of any other servers offhand that have SoF content available yet, but if there are any, I would definitely like to check them out to see how it is coming along
Hopefully, once the packet collectors are working again, SoF content will start flowing in much quicker for all servers. Until then, it will be fairly slow to make high quality content in the zones.