Image and text or two things that work in a weird sort of harmony. They can be used to speak of the same thing, like in the book From Inside. Text can be used to create mental images in the mind of the reader. Image gives the user a palette to work with but the true story remains obscured by the lack of words. Currently it seems that the roles of image and text are used in harmony, but do not interfere with one another.
Text holds the true power.
News stories will write the words with text, and there will be a spattering of images throughout the article and maybe a sound byte as well. This current agenda does not to seem to be changing radically. The web as a system is faced with many bottlenecks. The web is slow and the extra graphical touches a web site is given will almost always contribute nothing, and only confuse the reader. As higher bandwidths emerge the only real changes I believe we will see is going to be a lot more animation.