I missed this when it happened. According to Grid.org:
On Friday, April 27, 2007, Grid.org announced it has completed its mission to demonstrate the viability and benefits of large-scale Internet-based grid computing, and will be retiring its famous efforts to support critical health research.
Grid.org projects included research in cancer (with Intel), anthrax (with Intel and Microsoft), smallpox and the human proteome folding project (with IBM). As of last month Grid.org managed almost 4 million devices belonging to 1.3M members who donated over 210 CPU years each day.