Hi,
The Cognos 8 release includes both the new Analysis Studio, and the old PowerPlay Client and Transformer. Transformer remains as the tool to create Cognos PowerCubes, and PowerPlay client is provided for those users who require "Mobile Analysis" (ie they want to be able to access cubes locally on their PC rather than through a web browser).
If you don't have Analysis Studio, then you probably need to talk to your Cognos account manager.
Best regards,
MF.