Id love a new class or two, but mostly i'd like then to overhaul the class 'build' system. There isnt enough variety, and in my opinion the classes are too similar. They need more defined roles. Titans need to actually be tanks, etc. If I had it my way (which I know I wont), I would make each class have all the same 'core' abilities. Then the subclass would give additional specific 'minor abilities'. Then let us tweak the subclass builds a lot more, and more stats to build on.