All of these moves and feats are super cool, but still not anything that anyone with a modicum of common sense would attempt during real combat, unless they absolutely had no other choice.
I truly enjoy seeing such representations on TV, in movies, and in RPG's. But, these are nothing but exhibitions, even the acrobatic guys. Granted, the really good ones could do that stuff all day long, but someone truly experienced in combat (as opposed to just trained for it) knows better than to do anything that purposely places them in a do-or-die situation. Even one of those incredibly talented acrobats occasionally misses. The problem is, from a real-combat point of view, a miss almost assuredly means death (whether from injury from the mis-step, or an enemy taking advantage of your mis-step - a real coup-de-grace, not an RPG one).
In real combat, when one makes an offensive move, the smart opponents (those that live long enough to be experienced combatants) don't do it without planning to, and attempting to, finish in a defensive position. Just in case they miss. You never purposely put yourself in a position where, if you miss, you will probably be killed yourself. Remember, a wound in real combat doesn't just take away a few hit points, it's more likely than not Game Over. Nothing is guaranteed in combat. It may be boring and conservative, but in real combat you play the odds. If failure of an attack or maneuver would result in almost assured death, you usually don't do it. The law of averages catches up with everyone eventually.
Jackie Chan may be able to do some incredible things on film, but just watch the blooper reels and you'll see he misses almost as much as he succeeds. Jackie Chan could beat most people in a real fight, but I'd guarantee you'd see absolutely none of the stuff you see in his movies. It would be quick, brutal, efficient, un-flashy, and boring - but he'd kick your ass nonetheless.
But, (my being a Buzzkill notwithstanding) these videos are excellent examples of special RPG maneuvers and powers. If you like the no-holds barred but unrealistic fights that happen in movies today (ala Jakie Chan, Chow Yun-Fat, Jet Li, Jason Statham, etc.), then allowing such maneuvers in an at-will manner works. If you want a more realistic approach, then encounter, daily, or action point only, fits better. I think 4E has done a fairly good job of striking a balance between simulating real combat, and an all out reality-break like a Jason Statham movie. The feats presented in these videos are an excellent example of 4E powers, and certainly very entertaining - just like most RPG's are designed to be: Entertaining.
