I was sent a survey by MLS today, asking questions about the playoff format.
The most interesting questions were:
(1) Am I aware of the away goals rule?
(2) Would I like to see the away goals rule adopted in the playoffs, or do I prefer the current format?
This shows that they are considering a change, and seeing how it will affect their fanbase.
Personally I am in favour of having the away goals rule, and most Americans are now familiar with it through the CCL, if they weren't from Europe.