What does integration mean to your SAP implementation?
Over three thousand organizations are using the SAP NetWeaver Process Integration (SAP NetWeaver PI) offering as their enterprise-class, service-oriented architecture (SOA) middleware to perform application-to-application (A2A) and business-to-business (B2B) integration, and to accelerate composite application development.
If you read that carefully, the scenario described above is not very broad. What about mobile-to-SAP? What about Microsoft SharePoint connections to SAP?
PI is best used with asynchronous communication which is described in the Best-Built Application Guide: https://www.sdn.sap.com/irj/sdn/bestbuiltapps?rid=/library/uuid/d0619693-ce8f-2c10-07b5-fc222ad36370.
One of the most interesting new products of SAP is Netweaver Gateway and in particular the 2.0 release.
Gateway allows you to expose your SAP systems with REST HTTP service calls instead of cryptic BAPIs. Or, even highly complex SOAP services (that are better suited for PI). REST is a really simple and fast web service interface that is extremely easy to integrate. If you aren’t familiar with BAPI’s, they can be very powerful and critically useful. If you are an ABAP programmer they may even be easy to use. However, to a 3rd party, or anyone integrating with SAP, these are downright cryptic: