Bruisers nerfed more. ADCs buffed more. Assassins nerfed more. More mages in the support role driving out traditional supports. Top lane becoming more and more about ranged champions, even possibly being another lane for a "safe" (re: high mobility) ranged carry: either a mage or another ADC.
Item changes are made to further reinforce these decisions. Champions that have been left in the gutter for far too long (Garen, Darius, Olaf, etc) are left there in spite of outcry for them to be made better again.
New champions that are released further cement these changes with both high mobility as well as nerfs to those champions that are released (about a month after release) that would violate this particular system.
The game becomes primarily about right clicking or instant burst combos. Tanking dies out.
I have no information from Riot, but the changes made at the start of this season and during this season seem to point towards those overall trends.