I was thinking that it would be nice if there was a time-skip at the end of Encore! I say all this because the whole idea of the manga is about these kids's quest to finding their true selves and whatnot. Therefore, I think it wouldn't be nice we are all left to make up on our what happened at the end, don't you think?
Amu could retell us what happen after certain number of years passed (at least 3-4 years) , most probably when she's finishing High School, gives us an insight to what happened to the other characters and what's happening to her now.
Some good way to show time skip, is that P-Pit show Amu more developed (ie physically) & probably with longer hair to hint at the years that have passed.
Amu could b like "after I recovered my Charas this happened... then that..." & so on. Mayb she give us some preview about what happened to the other characters & also include whats happening to her now, e.g. "I'm finishing my High School now & hope to study Fashion Design..." (or something as such).
Maybe say what happened when Ikuto came back or if he still has to come back.
Also with a time-skip, if Amuto is going to happen at least it wouldn't be too controversial
:( sorry folk i'll only be on weekends now >.<