From the FAQ on their website:
Has TG been acquired? Yes, VMware acquired Tungsten Graphics on November 26, 2008. The addition of the TG team will augment VMware’s ability to deliver industry-leading 3D graphics virtualization capabilities.
How does VMware fit into the landscape of open source graphics? VMware has had a history of developing technology to enable graphics capabilities to guest software running in VMware virtual machines. This work includes special drivers that are optimized for VMware’s virtual hardware, that consequently offer better performance and additional features such as arbitrary screen resizing and multihead support. The video driver was released as open source in 2002, with development done upstream in X.org’s git repository.
What does this mean for my open source driver project? Gallium makes it much easier to create 3D drivers that support multiple API’s on multiple operating systems and utilize multiple GPU architectures. Our team will continue to drive the Gallium infrastructure forward and keep it up to date with the latest advances occuring in the graphics arena. The means your Gallium based driver project will benefit from these enhancements.