In startup terms, "Roll Out" generically equates to launch.. as in release a product for use outside of the company.
"Roll out" is used more frequently in corporate / enterprise circles - esp. where development and deployment costs are budgeted & tracked independently.
Some project deployments are relatively simple (launching a blog, for example) - while others require migration of existing data, coordinated training, etc. Products that require complex setup tasks sometime refer to a "roll out plan" that details what is needed to use the product-- esp. when the cost to roll out the product exceeds the cost of the product itself (Think SAP).