thank you for your opinion about Needle. Of course we are interested to combine the experiences of both worlds.
A few weeks ago I discuss with Ales Justin about a Needle extension for Arquillian. I'm not sure if that makes sense. If a test case based on mock objects and the behaviour are trained with Mockito or EasyMock it is not possible to switch without code modification to a in-container test. On the other hand, with a Arquillian extension it would be much easier to migrate from a mock test to a container test.
In our projects we using currently both frameworks: Arquillian for fine-grained integration tests and Needle for fast unit tests.
I am looking forward to the discussion with the community and the opinions regarding Arquillian, Mock-Objects and Needle.