In the summer of 2011, Yahoo! released an incremental publishing feature on certain Yahoo! pilot stores. It has been announced that this same publishing feature will be applied to all Yahoo! Merchant Solutions and Yahoo! Store accounts, in phases beginning today, and on April 10th.
The new feature alters how users publish their stores, and adds new publishing buttons to the interface. There is now "Publish Changes" button on the Store Editor, providing users with an incremental store page generation capability, and allows the decrease of total page generations and publish times by generating only the pages a user has altered since their last store publish. The new "Publish All" button replaces the old "Publish" button, which posts all of a user's store pages:
Users should take into account that after this new feature is enabled, the first new publish attempted will require a full site generation and publish cycle. Because of this, the initial publish might take a bit longer than usual, but this is to be expected, and should be a one time occurrence.
For users with the pilot stores that fell under the initial implementation of this feature back in 2011, there will be no publishing changes - a full publish and site generation won't be required, if a user has already done so in the past.
More information on this can be found at the Yahoo! Stores help center.