This is Just an Unofficial Web Page with nifty Ideas! See what will and won't apply below.
What will be applied:
Other modes
More Options
More Stage Builder options and parts
More Items
Remember, things that will apply doesn't mean it's accepted, so make sure it's Nintendo Friendly!
What Won't be applied:
Characters
Official Stages
Trophies & Assist Trophies
More inappropriate things
Online Chat from random people
Custom fighter
Custom drawings of stages 
What's very important:
Bug Fixes
The DLC brawl shopping system(using smash coins)
More Ideas will come Soon!