There has been some interest in using Sharepoint as an EDC. We have attempted doing so ourselves and found its limitations for actual data collection are significant. Put another way, the amount of effort it would take to write code on top of Sharepoint to make it useful as a data capture and management tool was substantial.
However, Sharepoint excels as a document management tool and can serve that role very well. Most EDC systems do not support document management out of the box. This makes a combination of Sharepoint and an EDC system a workable one.
This white paper describes the features and capabilities within Sharepoint and its associated technologies that can help ensure 21 CFR Part 11 compliance: http://download.ehealthinformation.ca/cite/SharePoint-Guidance-21-CFR-Part-11.pdf