Yes RC2 is different from the full release, why would you expect it not to be Nina? The current release evolved from RC2, it's not like it was a seperate project or anything.
I think Joe is stating we had a heck of a lot more feedback in the full release than in RC2, that's all. If you want to interpret what "few" means then go and have a look at Gemini and get the hard facts (generate a report, give us the hard facts, DIY). Anyway retrospective is always a good thing, but the quicker we get bug reports in the better it can be evaled that a release is ready. We just can't do ALL the bug testing ourselves.
Yes I'm sure there are some changes that could not have been detected in RC2 (it would be impossible not to avoid this unless we are totally bug free), but there are a heck of a lot of issues in RC2 that could have been found out (FLAME ALERT: before anybody says I'm blaming the community for this - I'm not).
I think others make very important points as well, so please let's not have a competition on who is right or wrong... I actually think everyone is more or less right it just depends which view you take (I too have my own views that I'm not expressing here), but understand the phrase "Release Candidate" is a message to the community that states "please test", if they are prepared and able to do it that is, The number afterwards directly after the word "RC" I would say is fairly insignificant factor; understand DNN 5 had 7 BETAs (from memory, correct me if I'm wrong).
As to making release dates public, this is difficult as well, as if we go over the "deadline" we will hear no end of complaints from that angle. We cannot win either way, everybody has different ideas.
Anyway if you want the cold hard facts then be sure to follow Gemini, the forums, the blogs and contribute. Put your energy and time into this... Warning - this is time consuming, but every little helps.....