From Wikipedia:

New Age is the term commonly used to designate the broad movement of late 20th century and contemporary Western culture, characterised by an eclectic and individual approach to spiritual exploration. Self-spirituality, New spirituality, and Mind-body-spirit are other names sometimes used for the movement.

It is also commonly understood as the transition into the Age of Aquarius from the Age of Pisces in astrological terms. The new age movement usually centers around preparing oneself for a change in reality and consciousness. It is widely believed that a new age (era) is about to begin and love, peace and harmony will be restored on Earth, hence creating the idea of heaven on Earth. It is proposed that Humanity will then return to an understanding that we are all connected to the Divine and all are aspects of the One, All That Is, Source, God or whatever we wish to call it.

The Mayan calendar is also due to end on 21st December 2012, marking the end of an old era and the beginning of a new one.