Pyrewood Village EU PVE, playing casually but no queue times. My understanding is that for EU Gehennas, Golemagg, Firemaw and Thekal are the only EU English servers with issues, the first three massive realms and Thekal the new PVP realm.
At the end of the day, Blizzard offers free transfers but people don't want to take them, especially with such big realms and things being server specific (questing/dungeons/raids) being on a small realm really limits your opportunities. Everyone goes to these big servers or new servers because that's where the population is. Sure Blizzard could open additional fresh realms but I don't think that helps in the long run where the population splits, decreases rapidly after release and both realms end up as dead in a year. If anything I think they might consider a new server (PVP likely) after Phase 1 is in full swing if things are still a problem.
As for Nethergarde Keep EU PVE, I started playing on there with friends but when I came back to Classic at the end of TBC it was much quieter and my friends had moved to Pyrewood. Based on Ironforge.pro I'd allow free transfers to Mirage Raceway/Pyrewood and close it off.