If MS is creating a competitive product and expanding market share, good for them! That is big news for them. As you so correctly noted, this is just what is expected from every other company on Earth, but so novel and exciting to see Microsoft trying to do it.
This really could be a stroke of genius on the part of MS. A CRM tool is only as good as the information that goes into it. If everybody on the team is not disciplined in putting good information into the tool, then garbage-in-garbage-out. The genius that I see here is this is a CRM that leverages a platform where the customer wants to put into it as much work-related information about themselves as they can. My LinkedIn network isn't that big and I see a constant stream of things where people are patting themselves on the back for some new job, certification, or other such thing. From a sales perspective, each of those events represents a potential opportunity to engage, or a lead. It would be the equivalent of each time a mention something cool I did at work it was via an email to every salesperson with whom I had come into contact.
If executed properly, this could be a rather significant development in the CRM space. This is especially valuable because as a salesperson, everything depends on timing and the LinkedIn activity feed is nothing but a stream of potential cues: "I see that John just took a new position at his company. Now is a good time to connect back up with him and see if there is anything I can offer to help him in his new role." That is not the sort of insight you typically get form a CRM system.