Dave Daniels
Founder at BrainKraft

Be in the driver's seat. Product marketing managers are the CMO of the product. Launching a product is a campaign ("series of connected activities designed to bring about an accelerated result"). When you think about launch that way it changes your entire perspective. You define launch goals, put metrics in place, develop a campaign strategy, build campaign elements, identify/close readiness gaps, etc. 

Be large and in charge. Take the reigns. Go big or go hom. [Other trite corporate-speak saying goes here]