XGI never ended up shipping their discrete PCI Express graphics cards, and with that hope was lost in XGI Technology becoming an interesting open-source company. XGI is still in business, but they just focus on server IGP chipsets and other embedded solutions.
About a year ago, we were greeted with news that open-source Linux support for XGI graphics weren't completely dead. Ian Romanick, an X developer who was working for IBM at the time, had written XG40 DRM support for the the Volari V3EX, V3XT, V5, and V8 graphics cards. In August of 2007 prior to the release of X.Org 7.3, Ian released the XGI 1.5.0 open-source X driver. It was then revealed that IBM was funding this open-source XGI work as they were shipping an XGI XP10 graphics processor in a PowerPC server.
Since then, we haven't heard anything about XGI Volari improvements for Linux nor have we seen any code commits to the driver's development tree. Today though we have found out that Ian Romanick has left IBM. When leaving IBM, he had returned his hardware and unpublished documentation back to the original sources. With that said, it looks like the final chapter has been written in the XGI Linux book.
The good news though is that Ian Romanick has joined Intel. Ian will be serving as the "OpenGL guru" for Intel's Open-Source Technology Center (OTC) where he'll be working on improving their OpenGL support. Ian will be addressing OpenGL issues, working to get the GLX protocol working for buffer objects, and he'll also be responsible for improving the performance of Mesa and their drivers on multi-core processors (read: SMP driver optimizations and Mesa performance improvements in time for Intel's Larrabee discrete GPU).