So far (on master), slated for removal (and currently with compiler notices upon use):

• short function syntax - f(x) = x - [currently has notice]
  why: hacky implementation, duplicating functionaly
  use --> to make curried functions
• +++ concat op [currently has notice]
  why: added ++ as concat op, which is shorter and better
• where statement - relatively useless - just use local var assignment or a let statement [currently has notice]
• undefined alias for void - added for CoffeeScript compatibility, but with coffee2ls that is not an issue [currently has notice]
• !? inexistence op [currently has notice]

discussion:

• choose one of ** or ^ for power op?
• remove import and importAll?
• remove x is not y to mean x isnt y, have it mean x is !y instead
• yes/no/on/off aliases - added for CoffeeScript compatibility, but now with coffee2ls, this is not an issue

More controversial:

• remove standalone use of @
• remove standalone or hanging use of ::