Disney have updated their original details about Main Street Bakery becoming a Starbucks location from next year.
Clarification has been provided about what's actually going to happen to Main Street Bakery. Guests will be happy to know that Main Street Bakery will be retaining its name and menu of baked goods. Here's the full details from the Disney Parks Blog:
UPDATE 11/12: Here’s some additional information about our Walt Disney World Resort Starbucks locations. The Main Street Bakery will keep its name and theming when it reopens in early summer. It’ll also continue to serve Disney favorites like cookies, brownies and seasonal cupcakes, in addition to Starbucks signature beverages and other items. And for those of you who asked in comments, the cinnamon rolls are available at Gaston’s Tavern in New Fantasyland, and the ice cream sandwiches are available at Plaza Ice Cream Parlor on Main Street, U.S.A.
For what it's worth, WDWFans attended the Enchanted Forest soft opening, and the Cinnamon Rolls on offer at Gastons Tavern were not the same as the ones Main Street Bakery offers. This may however only have been for the soft opening. Enchanted Forest is due to open on December 6th 2012.