Many or even the majority of folk who think something big will happen 2012, think that it will be something positive (I don't, but hopefully I am wrong...)

The most scientific happy ending theory involves "a kind of singularity, a radical change in the nature of things, or at least the nature of humans will occur that year." Basically, a point where our rate of change and invention as humans reaches a maximum, and some sort of blissful explosion of love and intelligence occurs. Follow the link the read the best single page on this idea I have come across.

Source: NeoFiles: Psycho-Spiritual Transformer