that would kill D&D for me and my group unless 5.5 is huge
5E is successful so I do not expect "huge" changes in how classes look.
but I do expect removing the "feats optional" default,
moving towards pointbuy/array as default ability generation, same as fixed HPs per level
possible return of 5min short rest for using HDs and moving most abilities towards long rest or at-will
all races will have +2/+1 or +1/+1/+1 maybe +2/+1/+1
everyone having a feat at 1st level and most likely at 4th level in addition to class gives ASI's
All classes having 6 "slots" for skills, armor proficiencies and cantrips at 1st level. Additional depending on class in next 2/3 levels.
0 additional for multiclassing
With max and min limits for every class,
I.E:
figther:
armor; max heavy (3 slots), min light (1 slot)
skills; max 3, min 1
cantrips; max 1, min 0
rogue:
armor; max medium, min none
skills; max 5, min 3
cantrips; max 2, min 0
cleric:
armor; max med, min none
skills; max 3, min 1
cantrips; max 4, min 2
wizard:
armor; max light, min none
skills; max 3, min 1
cantrips; max 5, min 3
ranger:
armor; max heavy, min light
Skills; max 5, min 1
cantrips; max 3, min 0