OpenChrome's Xavier Bachleot wrote a mailing list message announcing the release of two new VIA documents. These documents cover the graphics core / 2D engine and 3D / video for VIA's Chrome 9 IGP, specifically the VIA VX855 and VX875 ASICs.
The VIA VX855 media system processor has been on the market now for almost a year, but its largely derived from the VX800 that has been around for two years. It hasn't taken VIA Technologies all this time to assemble the documentation and then release it, but it's clearly stated on both documents "Preliminary Revision 1.0; July 29, 2009." In other words, these documents have been around for at least six months before finally being uploaded for the public. It should have not taken a half-year either for these documents to clear VIA's legal review process. The OpenChrome developers have likely been sitting on these documents as well through their VIA NDAs for some amount of time too.
Both of these VIA documents are licensed under the Creative Commons and the core/2D documentation amounts of 110 pages while the 3D/video portion is 172 pages. These are the first public documents emerging from VIA Technologies since November of 2008 when they did their last documentation drop.
VIA's graphics processor documentation can be found on the X.Org server.