That is a wicked scene from a great flick, Donnie Yen is fantastic in the lead role and the Wing Chun is out of this world.
It is not my favorite scene taht would have to go to Jackie Chan in Police Story 2, the playground fight scene but I am HUGE JC fan so am a little biased.
Holy shit, that's some impressive chain punching at around 2 and 2 1/2 minutes. At my old place, my ex and his friends used to train in Wing Chun in the spare garage, and I thought their chain punches were fast, but that is just incredible. Wow.