This is greatly needed here in the U.S. and Canada, since at present we have nothing other than common sense and a tradition of controlling who gets access to HR data to guide us. The EU Directive and the Internet are driving issues in this area to the fore. As for data warehousing, I share your perspective and concern, but as of now we haven't seen or heard of companies here including employment data in non-HR warehouses. Our committee did plan to issue a white paper on the topic, but unfortunately it never was written. There are ways that HR data could be used in a safe manner in a warehouse, e.g., via anonymizing or aggregating.
Vendors can also help, particularly where there is market or regulatory pressure.
We are at the dawn of the true information age, and need to take steps to ensure that proper safeguards are built in from the beginning. I am pleased to provide insight into my experiences regarding Data Warehousing of HR data. I have participated in three teams in the past where Data Warehouses were developed in order to provide an end-user reporting tool. Brio Query was selected as the end-user reporting tool in all cases. In two of the implementations, the Data Warehouse was supported by the HRIS staff.