In June 2008, CIO Magazine published, Eight Reasons Why Companies Still Say No to SaaS., based on a Forrester Research study.
Number one on the list was integration.
In May 2010, integration is still a hot topic, but the SaaS industry has made great progress by extending the API layer, creating platforms (PaaS) around their solutions, and forming partnerships with cloud application integration vendors like Informatica, Boomi, Cast Iron, and Pervasive.