Good & bad.

good - it shows mood of the environment if properly shot
bad - color not balance & don't look nice & especially if u are shooting a serious theme, eg. wedding, its best to manually adjust wehn u came from outside into the church.

The way to manual setting WB is point the camera on a white surface, an example will be plain A4 white paper, & I mean really white, not grey nor anything. Adjust your cam setting to Manual WB & within seconds your cam will read the light temperature, there u go, a balance color in view!

I don't recommend auto WB because CCD sometimes don't get the correct light setting.

White balance must goes with the present light situation, eg, if u go into a room with yellow light where everywhere is so yellowish, by using above method(point on A4 white paper) will make the yellow become slightly whitish, then it doesn't look original.