The Google App Engine team has been having a solid year with regular releases of enterprise grade features across regular monthly releases. The latest version 1.8.2 is squarely targeted at large scale application creation, better tooling support in Eclipse and updates to Python and PHP Runtimes.
App Engine has always allowed developers to increase Scaling/responsiveness of their applications via the free shared memcache service. They have taken it a step further by the introduction of a dedicated memcache, where you can opt for in-memory data caching capacity exclusively for your application. This service is not free and billing application can utilize this service at 12 cents per GB per hour.
The release also sees attention to Developer productivity, which is likely to be a key differentiator among similar competitor services. If you prefer staying in the Git environment, you can now use the Push To Deploy feature for your PHP and Python applications. The Eclipse Google Plugin now has WTP, EAR Files and Maven support.
Next up is the runtime for Python, which has seen its interpreter being updated toPython 2.7.5. The PHP Runtime is fast becoming popular among PHP Developers and it sees support for additional extensions like mcrypt, include PHP scripts directly from Google Cloud Storage, a drop-in plugin for WordPress and Mail API support.
Google App Engine has primarily supported Python, Java and Go runtimes. At Google I/O this year, they announced support for PHP runtime, which was one of the most requested features. Andrew Jessup, Product Manager for AppEngine has said in an interview that they have been amazed with the response they have had for PHP and while he did not state the numbers, he did mention that it was a lot.
For more information on App Engine 1.8.2 Release, refer to release notes.