This is a major revision to the Ecommerce Suite. 
Please have backups and test properly before upgrading. 
You must follow a manual upgrade procedure if upgrading from CGEcommerceBase v1.7
After upgrading this module, and all sub modules you must visit each sub module and click a button to activate that module within the ecommerce suite. This release breaks backwards compatibility with older shipping, tax and cart modules. Check for updates to these modules.
Re-work PHP interfaces for shipping, tax, payment, handling, and other modules. Because of the way PHP interfaces were implemented, it was impossible to implement an upgrade path that allowed users to use the CMSMS ModuleManager to get upgrades from the forge.
Adds new interfaces for promotions modules.
Re-work the user interface for sub-modules in a dramatic way. Shipping, tax, payment, handling, packaging and cart modules now use a button within the module to indicate that that module should be used for a specific type.
Adds extensive use of namespacing, though not complete yet.