Udo: No, as I have already stated, no random number tests yet. Yes, you should regard it with suspicion for crypto and gaming applications until testing is complete. You have access to the library though, so by all means test it yourself. It looks like Diehard needs some big data sets though. I'd also suggest having a look at the random.org tests: http://www.random.org/analysis/
, as they seem to prefer the more actively maintained NIST tests: http://csrc.nist.gov/groups/ST/toolkit/rng/index.html
However, in its current state, it is still very useful for unique identifiers, discriminating different Arduinos with identical software, and of course amusement purposes such as die rolls and magic 8 balls.