Warmane WOTLK has a decent community and playerbase, although not that big*.
They launched a Cata server too, which is also pretty much dead.* I am not aware of any other well scripted and/or populated Cata server.
As for MoP, pandaWoW was hiped for time, not sure how it is now. There is a Hungarian MoP server, in fact one of the oldest private servers still running since vanilla: Tauri. Mostly populated by Hungarians, but it's well scripted and has a big playerbase - there is even a twink community (have a lvl 69 twink mage since TBC there).
Warmane is btw hugely responsible for it. The ruined both arena-tournament AND Molten-WoW (the former was the greatest arena/bg server of all time and the latter was a really decent Cata server). Sure, they launched the progressive WOTLK Loarderon, but that's too little gain for the losses.