I too found it strange at how the whole thing happened. There are different ways to look at it, but one way is that there are people in California who couldn't make it and will feel slighted since they were unable to make the conference yet are users of the program.
If we were a month away from the release, I could see not wanting it out, but I think posting it on the website is a guarantee people will download it. It is much like putting a bone in front of a dog and walking away and expecting the dog not to go after it.
I, as you John, think the development cycle is rather strange. While much larger companies can't afford to just throw up a Beta to 30,000 customers, I think AC can do it differently.
Say, 5.029 is the official release. Not alpha or beta. You are using it, and given you are up to date on your support contract, yoiu get full support. Subsequent updates, which should be in the opinion of AC will be very near the final release could be available with the understanding that it will not be supported or, at the very least, only email supported. Users could then report bugs on one forum which would be entitled Beta reports.
v6 could be put out in much the same way. Maybe after one month of Beta testing. Users could then use it and multiple feedback would occur giving AC an advantage most companies don't have. Limited support would be available with most of AC support concentrating on v5.
To be honest, I test it on VM as well, but it is not until you use it on a day in and day out basis that the bugs will be found. And, while users like you and I may not use it in production, with 3500 users, there are plenty who would.
I may be way off on the support for it. Possibly, there could be 20% of the support staff that work specifically with v6.
