This is a slightly old interview with Microsoft’s Scott Schnoll where he talks about backup strategy in Exchange 2010. While some customers may find this to be an outrageous concept, he talks about how Exchange 2010 database replication can address most, if not all of the reasons you would traditionally backup Exchange using legacy backup technologies.
Every organisation has different requirements, the challenge is balancing these requirements while we embrace new technologies and evolve the way we think about things.