Blended worship means different things to different people.
Some refer to blended worship if it sneaks in a praise chorus now and then, or is very informal, or uses folk music. This is not what I mean by blended worship. Blended worship is that worship that tries to seriously mesh traditional elements with newer elements in a seamless way. The only place I see this working is in new churches or in additional services add to the existing services. In most cases I've seen, blended ends in a very unhappy congregation.