As is often pointed out, ...
As is often pointed out, knowledge is a two-edged weapon which can be used equally for good or evil.
As is often pointed out, income-tax is a two-edged weapon which, on the one hand, narrows the gap between the haves and the have-nots, and to some extent dampens the passion of the former on the other.
What characterizes almost all ... is ...
What characterizes almost all Hollywood pictures is their inner emptiness.
What characterizes almost all TV programs is their monotony.
What characterizes almost all newspapers and magazines is the excess of commercials.
Whatever ... , one thing is certain / clear
Whatever the source of noise, one thing is certain: Silence, it seems, has become a golden memory.
Whatever the results of this investigation, one thing is clear: Violence like this has no place in this country.