If you have read the July 15, 2013 (Study Edition) Watchtower as a Jehovah's Witness, it means the following to you:
-The Watchtower Society had previously asserted that a Faithful and Discreet Slave Class has been in continual existence since the first century. That has been abandoned.
-CT Russell was a member of the faithful slave and passed on the 'truths' of the Faithful and Discreet Slave into modern times. That has been abandoned.
-The Watchtower Society has always taught that the Faithful and Discreet Slave is all anointed ones on earth. That has been abandoned.
-The Watchtower Society had rejected the idea in the past that the Faithful and Discreet Slave is a small, elite group in the Organization (See March 1, 1981 Watchtower, pp. 24-26). Now, it teaches precisely that idea, and calls what it used to reject as "apostate" thinking, "new light". That is new.
- The Faithful and Discreet Slave is now exclusively the Governing Body (A few men residing at the Brooklyn headquarters). That is new.
-The Watchtower Society used to teach that Jesus came invisibly in 1918 or 1919, inspected the Bible Students, chose them and appointed them over all his belongings. This has been abandoned.
-The Watchtower Society now teaches that Jesus appointed Rutherford as the first Faithful and Discreet Slave member in 1919, and appointing them over all his belongings will not happen until he arrives in the future. That is new.
-The Watchtower Society used to teach that only the anointed were part of the domestics. This has been abandoned.
-The domestics are made up of both the anointed and great crowd. This is new.
Essentially, the Watchtower Society has abandoned core doctrines it has held as absolute truth from God for decades - some close to 100 years - and, without admitting it, is now teaching those doctrines were false, replacing them with new beliefs.