A credible source has given more details about Android 2.4 still being called Gingerbread. The main difference between the two versions (2.3 and 2.4) will be thorough support for multicore processors and how the OS can best take advantage of the new horsepower.
Additionally Google Talk video calling will be integrated and match the support level in the Honeycomb OS. Lastly it will incorporate the ability to run the new dual mode apps that are designed for Honeycomb and correctly scale them and appropriate the "fragments" accordingly. This is not a major update as signaled by keeping the name Gingerbread, but one that will bring support for new hardware and software being released currently and in the near future.