Here are some of the booth schedules I have found:
Autodesk
http://area.autodesk.com/siggraph2012
Pixologic
http://ugm.pixologic.com/registration/1208-Siggraph/
The Foundry
http://www.thefoundry.co.uk/articles/2012/07/26/369/the-foundrys-siggraph-schedule-booth-1019/

AMD
http://global.amd.com/LP=453
NVDIA
http://www.nvidia.com/object/siggraph-2012.html