First, as discussed in the presentation, IBM Business Monitor is an event processing infrastructure for the purpose of visibility. So Business Monitor is constantly actively correlating events, calculating metrics and detecting alert conditions. These are capabilities not typically found in a BI/reporting tool.
In addition to this, Business Monitor includes a dimensional reporting engine - using the technology from IBM Cognos BI 10.1. This is used to provide reporting of your current business performance and compare to the recent past (history) via various dimensions. You can also use the full Cognos BI with Business Monitor. For example, if you have Cognos Mobile, you can use that to interact with Monitor information on an iPad, iPhone, Blackberry, etc.
So Business Monitor is very complementary with BI software.