I view this as a positive move; MMB had certainly outgrown its usefulness in terms of deployment planning or even simulating the type of load that one might expect from a production Exchange deployment. While there is still a need and validity in the load driving tools and some form of testing, the methodology and workload associated with the benchmark served little purpose beyond some level of server comparison.
HP currently provides sizing tools, reference configurations and best practices guides focused on assessing server, storage and deployment architecture needs for a given Exchange workload. These are freely available on our ActiveAnswers solutions portal (http://www.hp.com/solutions/activeanswers/exchange). Microsoft also has the Exchange Solutions Reviewed Program (as referenced above), which is effectively a storage solutions benchmark, which is a much better approach to providing prescriptive guidance for a given configuration in support of a specified workload. HP actively contributes ESRP configurations as well.