If you're wondering why we (or anybody else, for that matter) didn't note that the energy storage system used on Porsche's new 911 GT3 Hybrid racer was developed by Williams in our original post, that's because the Germans 'conveniently' forgot to mention it in their official press release...
Thankfully, Williams issued a separate release informing us about their collaboration with Porsche while the company also noted that the energy storage system was originally developed for use in Formula One by the AT&T Williams team (the KERS system), but now it is focusing on applying the technology in road vehicles through its Williams Hybrid Power subsidiary.