Well according to my 6 year old information from WoW, they used C++ for their servers and have a bit of a NIH streak.
So I am guessing it's probably still a C++ heavy shop like many gamedev places.
So I am guessing it's probably still a C++ heavy shop like many gamedev places.
To start though you need multiple inheritance likely to get this to work idiomatically. C would also do fine, as would Java, except the Java would look like C because of the lack of multiple inheritance/mix-in, while the C code could result in some type insanity -- although components can be implemented as simple structs in structs for entities, except the whole construction/destruction phase of life.
As an outsider looking in, C++ seems filthily well-suited to game development.