Greetings and Salutations ,
One of the key UI introductions in 8.56 is Classic+ ,seems like Oracle has tried to bridge the gap between Classic and Fluid. Classic+ will answer to the look and feel by introducing a unified UI as a wrapper on top of Classic.Nice thing is through branding Classic+ can be applied system wide.The Responsiveness though will be missing with Classic+.
Here is the 8.56 Highlight video
Also visit the Oracle Blog for more details
Here is the People books link for 8.56 http://docs.oracle.com/cd/E87544_01/pt856pbr1/eng/pt/index.html