Actually I am not sure that it has. Here in the early 21st century, In general I see a watering down and an acceptance of things that are not part of Wicca as it was initially set up . The following is merely my own opinions and thoughts on this subject and may change with constructive criticism and others replies.
The Positive Side
Some people might not agree, but it is just an opinion and observation, the academic community seems more interested in studying Wicca. Therefore we are able to put aside some of the common myths that people were taught say 40 or 50 years ago (such as that Alex Sanders was initiated by his grandmother when he was a child). I think the academics interest, and often their training in research methods, is a positive.
Many Wiccans are passing their traditions on to their children and yet allowing them to make up their (the children's) own minds about their spirituality. I think this is good as long as the oath-bound material is not passed on until the children have been properly prepared and initiated.
The Negative Side
The concepts of initiation and not charging for teachings have gone by the wayside in many instances. Much of the teachings of Wicca are oral and provided after initiation. Wicca has a format that many Pagan spiritual paths don't. It is one of the things that qualify it as a religion. You take away that format and it is no longer Wicca.
There is too much "crap" written that is purporting to be Wiccan. Just because somebody writes something does not make it accurate. Unfortunately, because Wiccans have in many ways failed to define themselves and often have failed to speak up and say - wait a minute that is not Wiccan, the lack of valid, adequate information has declined. Too many people who really don't understand what it means to be Wiccan, or know what Wicca is spread all manner of junk - and with the growth of the Internet it has gotten worse.
I don't know about world wide, but here in the US we live in a FED EX society. People want things now - without wanting to study and learn.
I don't care what people think about this, but I see too many teenagers running around, especially ones the look like death incarnate, claiming to be Wiccan. In most cases, they are not (most Wiccans won't initiate a person until after they have become an adult) - they have adopted the terminology as a form of rebellion.
This doesn't only apply to Wicca, but any magickal tradition. I see too many people using some form of magick without really understanding what they are doing. Some people are not only using magick but also teaching. I have sat in on some of those lessons and they are generally bad and the only thing I hope is that none of the student's attempts work. They are not only harming themselves but others, dishonoring the Wiccan's Rede: An' if ye harm; do as ye will.
Feminism, especially radical feminism, has been detrimental to Wicca. Wicca is a religion of balance; we worship and work with both the male and female aspects of deity. Too many people now think of Wicca as a "women's" religion. It is not. And when I'm told and have heard male practitioners being told - "Oh you can come in circle, but you have to leave your penis outside" I can't help but think these women are NOT Wiccan and are spreading a form of discrimination and hate and we're suppose to be about love and acceptance.
The schism between Traditional and Eclectic
If by eclectic you mean the I can call myself anything I want - I don't need any training - I don't need initiation - I have no responsibility to anyone but myself; I sincerely hope not. At this point, I don't see common ground.
I think that Wicca needs to evolve, but I don't think the basic principals should be discarded for the sake of expediency. Although I realize it doesn't apply to all eclectics, this is what I have seen with too many people who self identify as eclectics.
Finally Thoughts
Wicca needs to define itself and set some standards. In many ways, it has, but the problem is the definition is too broad and the standards are not enforced. Many Wiccans rather than standing up to those who claim to be Wiccan, but have not been initiated or have not received the teachings; just choose to go off with their tails between their legs and complain to other Wiccans that people are running around claiming to be something they are not. People who choose to be the "hidden children of the Goddess" even within the Pagan community are not doing anyone any favors and have only themselves to blame if others usurp the title.
