The bitcoin casino industry could take off because of this fairness advantage. People are always looking for fair casino games!
Why wouldn't existing casinos be able to do the same thing? There's no way to leverage the security of Bitcoin itself to ensure the fairness advantage. That's up to the site operator. Bitjack21.com has a client server scheme to prove fairness, but the only similarity to Bitcoin is that it probably also uses the openSSL library.
You are correct. Although I think the general idea of bitcoin and cryptography gave the concept of using cryptography to determine fairness a push. Check out this article. It's spreading!
http://siliconangle.com/blog/2011/08/29/bitcoin-delivers-confidence-for-online-casinos/
