I do understand, that we need a point, where we in respect to the MEL, go from the pre-flight to the active flight.
BUT it is not logical, that you make this transition MEL wise, when you start taxiing for takeoff. Why not keep it like it has been for years : the MEL is applicable until you set takeoff power. The MEL was made with that in mind.
Now, if or when you get a failure after you have started taxiing for takeoff, the correct procedure now, is to apply the abnormal checklist/QRH. But problem is, the abnormal checklist/QRH only deals with post takeoff failures, they have not been changed. So all the failures concerning e.g. antiskid, brakes, flaps, slats etc do not give you a performance penalty anymore, if you follow the new text to 100 %, because now you are in active flight. Off course I know, that most captains would apply common sense, but with this new MEL text, safety has been compromised, and I am sure that we will see incident/accidents in the future, due to crew taking off with failures that with the old MEL text were NO GO.