Install them and try your favourite content out with the betas.
If you find a bug, be sure to let Adobe know.
Finally, why not help spread the word by passing on details of this beta test drive via your own blog or twitter?
I want to add some more here in response to the comments so far. I thought long and hard over whether to get involved in this beta bug request as only this morning I was looking at a bug – ClassReference in nested CSS file compiled to SWF causes error – that was closed as “deferred” two years ago. Stefan Richter had highlighted it as an example of how Adobe mess up with bugs at times. The problem remains unfixed and Adobe’s communications were crap with this bug as they didn’t explain why they chose to ignore it. However, in the end I decided it would be wrong to focus on such negatives at the expense of the great stride Adobe have made toward openness.
They have a open bug reporting system. A lot of the flash development environment is open (the whole of Flex Framework for example.) Part of opening up to the community involves inviting the community to give back to the project, both in terms of bug reports and bug fixes. Adobe have frequently highlighted the fact that people are welcome and encouraged to not only report bugs, but to help fix them too. So to those that complain bugs remain languishing unfixed for long periods of time, I have a simple question for you: have you tried contributing to the openness of Flash by helping fix that bug?