After reading the interview from people in the so-called "middle class", sincerely I do feel that in Malaysia, earning a household income of above RM3,000 (gross income) is not considered as "middle class" but merely in the middle of Low-Income group and Medium-Income group.
Never mind the classification, it is no longer good to be in the middle class, USA has the biggest middle income group and now is suffering from higher effective tax rate and lower income prospect.
Work harder can only ensure survival, as the increase of cost of living is outrun the increase of salary, we need to work smarter as well as harder in order to enjoy a better life. Well, for me, work smarter include looking for extra source of income at lowest possible cost (i.e. required number of hours).
More reading: The Star, 16 October 2011, Tackling Woes of the middle class.