There is an ongoing effort to develop a SQLAlchemy data layer for Eve. This is interesting because it will allow the use of a wide range of SQL databases (PostgreSQL, MySQL, Oracle, etc.) as storage backends for Eve-powered REST APIs.
The current early prototype resides in its own sqlalchemy branch. We are in the early stages of development and contributors are invited to join the ranks. There is a lot of room for improvement at all levels: features, tests, documentation, you name it.
If you want to lend a hand please come visit us on IRC so we can better coordinate efforts. Jezier has been working on the SQL features while beatpanic has been playing around with the test suite. Get in touch with them or with me (I’m iaro on IRC). If IRC is not your cup of tea feel free to open a ticket, email me or submit a pull requests: just make sure it is against the sqlalchemy branch.