****, I just posted about this in the "new techniques" thread. here goes:
There are no lengthy combos anymore, technically speaking. However, there are lengthy, reactionary strings.
Think of it like chess: There are well-defined openings, playing by the book as they say. However, if your opponent does something that throws off your opening (like an airdodge), then you transpose into another opening (combo).
Another helpful chess analogy is the idea of forced moves. Chess masters can see things like "mate in 8" because they can see forced moves. This just means that you make a move which forces your opponent into a certain action which you then punish them for.
Say I'm sheik, and I want to:
ftilt 3 times into a dtilt grab. however, at any time in the ftilt string the opponent airdodges. I simply transpose into a different string of moves, say utilt dsmash or something.
The problem is, these same techniques held in melee, just as they hold in any decent game (video or otherwise), only now we don't have the tried-and-true ATs that everyone fell back on in Melee.
hope this wasn't confusing.