Clearly, things could get interesting on the search front as a result of this, but I suspect that MSoft is after Yahoo's visibility in the consumer market. If ZDNet is right, then going after Google, in search terms, isn't the primary motive:
Specifically, Microsoft says the combined companies can target the following areas:
* Scale economics driven by audience critical mass and increased value for advertisers;
* Combined engineering talent to accelerate innovation;
* Operational efficiencies through elimination of redundant cost;
* And the ability to innovate in emerging user experiences such as video and mobile.
Note that Blogger doesn't let me use Yahoo's exclamation mark :-)