On a (1.86 Ghz) Intel Core2 Duo machine with a weak (SATA 7200 RPM) drive I got the following results for tests run from the root of the bigbang-with-dependencies branch. Meaning all the unit tests for shared run as well.
For "mvn test" which runs 80% of the core integration tests with rollbacks:
1 Minute 40 Seconds
For "mvn -Dintegration test" which runs 80% of the core tests with rollbacks and 20% of the core integration tests with a pristine server (cleanup,reinstall,reconfig,restart).
6 Minutes 28 Seconds
Not too bad since we have not converted all the tests and nothing has yet been done for the server-unit tests. I think we can shrink this down to about 2 and a half minutes for all integration tests.