Have the Witnesses changed much? I would say absolutely. Not necessarily something tangible that can be quantified or seen easily; nonetheless, the Witnesses – at least the ones I have been exposed most to (Northeastern US) – there has been much change.
Referencing post 1970's, this has been my experience:
Mid 1980's talks about peace and security from the UN had the members really itching and zealous while still maintaining a sense of community and genuine sincerity to each other and even outsiders.
Things remained that way for the most part until...
The 90's Generation change teaching is when I saw the biggest internal shift in the attitude of the members. By late 90's gatherings and really building the social aspect of the religion nearly if not entirely died off.
Post 2000 - Just be at the meetings, obey, and be in field service. They are and will always be some cliques, but for the most part little to no interaction and socializing outside of the organization's meetings and arrangements; social gatherings near nonexistence outside of the occasional handful getting together.
Since my leaving the Watchtower Society in 2008, I do not know if necessarily there has been more change, but can definitely see the turning up the heat on shunning and obedience to the organization in the literature. However, like a frog in gradually boiling water, I'm not so sure the average Witness is noticing the difference. Regardless, that type of exposure, to that kind of information on a regular and consistent basis molds and shapes people’s thinking and actions.
What I'm hoping is likely the same shifts that happened with the 90's Generation teaching and passing of the year 2000 in the internal workings and attitudes of the members will happen again with the passing of 2014; nothing major (per se), no mass exodus, but a significant turmoil to the internal feelings and attitudes of the members. It may not result in a huge external show, but internally - psychologically - the passing of 2014 will (even if subconsciously) weigh on the members' minds.
I don’t want to see the members suffer (I believe/hope the majority of the Watchtower’s ‘sheep’ are good/decent people), but have enough internal conflict to create the necessary catalyst to think outside of the garbage the organization is serving them and break free. How many, how effective and subsequently how long until it motivates individuals towards steps to release the bondage is a guess at best.