I didn't see any summaries of the advanced techniques for Brawl, so let's see..
L-Canceling : Out
WaveDash : Out
Crouch Canceling : Less effective
Dash Dancing : Made useless
Double Jump Canceling : Out
Item grabbing/catching : Made easier
Shffls : Less Useful due to higher short hops and DI
Edge Grab : Easier
Pivot : Changed and not fully unserstood yet
Land Canceling B moves : Out
Turn around neutral B : In (According to someone who tried)
Am I missing anything?
L-Canceling : Out
WaveDash : Out
Crouch Canceling : Less effective
Dash Dancing : Made useless
Double Jump Canceling : Out
Item grabbing/catching : Made easier
Shffls : Less Useful due to higher short hops and DI
Edge Grab : Easier
Pivot : Changed and not fully unserstood yet
Land Canceling B moves : Out
Turn around neutral B : In (According to someone who tried)
Am I missing anything?