The line between media convergence and multimedia journalism isn't nearly as thin as it would seem. Convergence refers to the more "macro" end of journalism, as in a single company owning any combination of media outputs. This would include something like one publisher owning a TV station and newspaper functioning in the same general area. This would allow for one journalistic view or motive to take over multiple outlets and reach (conceptually) many more people than it usually would.
While obvious, an example of this would be multimedia news corporations such as NBC News. Though not aimed at any particular area of the country or world, they have taken not only to television, but also have garnered a heavy internet presence. This breaks down into ownership of several smaller outlets as well, and the massively popular MSNBC channel and site. Considering their owner, Comcast, that reach is far and varied. Multiple elements of journalism are all manipulated and held by one company.
Multimedia journalism, while related, is more along the lines of converging technologies for any one outlet. An example would be The New York Times website and blog. While there is of course the daily paper, the website works with it to keep updated on stories that may have been included in the paper. The blog does likewise, allowing for up to date, more personalized articles on a given subject. This allows for performance across multiple platforms, from print to personal computers and mobile devices.