Many companies deploying SharePoint globally struggle with whether to buy the Standard or Enterprise license. Although SharePoint takes advantage of User CALs (Client Access Licenses), previous versions required an entire organization to either have the enterprise CAL or the standard CAL (all or nothing). One area that this impacted, for example, was Business Intelligence. Frequently, departmental solutions looked to take advantage of the powerful Team BI capabilities provided out of the box; but these small solutions did not necessarily "tip the scales" for the entire organization to move from standard licensing to enterprise licensing.
Starting with SharePoint 2013, Microsoft is providing the ability to mix and match license types (i.e. Standard, Enterprise, Project, and Office Web App Edit licenses) within the same site collection. Using PowerShell, people in various AD groups can be assigned to the different license types. This changes the functionality that different users see within a site. Changes can even be made on the fly (i.e. without logging out and back in). For example, a user with an Office Web App Edit license would see a link to edit within Office Web Apps where a user without a license would not see the link.
This change would allow a company to start with Standard, then have Enterprise license upgrades approved on a user by user basis through approved projects. It also enables the departmental BI solution.
Another note on licensing… It seems that at least one additional server will be required in most Enterprise farms for Distributed Caching. Office Web Apps will need to be on its own server outside of the SharePoint farm.
At the 2012 SharePoint Conference, Microsoft also announced licensing around the social Yammer product. Microsoft is clearly pushing to move more and more customers to the cloud, which is evidenced by the fact that enterprise Yammer licensing will be included in the existing Office 365 E1 plan (at no additional cost). For on-premise customers, enterprise Yammer licensing will cost $3/user/month.