I am the creator of etheroll.com - it is a provably fair dice game, built on the Ethereum platform (you can view my story on etheroll here (I was in the middle of my 14 day crowdfund when the DAO hack begun), and I have been keeping a close eye on RANDAO progress etc.
RNG in computing is hard. On a blockchain, damn near impossible,due to the deterministic nature of the blockchain. I have spent a year looking into solutions for it.
It is (one of) the holy grails of blockchain, as far as I am concerned. I currently use oraclize.it and random.org to create RNG using atmospheric noise to create our RNG, however on-chain RNG is a much more suitable solution, as it removes the need for trust in a centralized entity, which is, of course, what we are all trying to do in the crypto space.
This is probably the best video from Vitalik Buterin I have seen. He touches on RNG for the first few mins...
Blockchain and Ethereum Security on the Higher Level - Vitalik Buterin
Thanks for this post. Followed and upvoted.