One of the things we'll be covering more closely on ProgrammableWeb is open web APIs in the enterprise. There's a huge opportunity for new APIs and mashup techniques to make a impact on how software is developed behind the firewall in corporate IT. This includes APIs from software as service (SaaS) vendors Salesforce.com and Cisco's WebEx as well as any other suitable API from the Basecamp API to FedEx to Google Maps Enterprise. More recently added entries from established players include APIs from on-demand providers NetSuite and Employease.
As of now there are a dozen APIs tagged "enterprise" but this number is sure to grow quickly as this space takes off.