UPDATE: Upon further consideration, I am wondering if Apple allowed (v62) to be leaked.   I mean Apple legal is pretty much on top of things and there hasn't been any other leaked builds of Safari that I am aware of.

It seems to me that they (Apple) have alot to gain from this beta that includes the no. 1 most requested feature to fall into the hands of the Faithful.  Interesting.

Recently there has been a lot of hulla-bullu surrounding the leaking of 1.0 beta (v62) of Safari.

If you frequent the blog of the most excellent David Hyatt you will see the most compelling evidence to move Safari to a nightly build system.   In this post you find that a early, motivated adopter had found a bug in the aforementioned version and word travelled back to the ears of said Hyatt allowing for the bug to be squashed, post haste.   This sort of squashing could be the norm, not the exception if Apple would see to fit to release periodic binaries; it wouldn't even need to be a nightly, I would be happy with a weekly checkout from CVS that is compiled and offered for Bleeding Edge types.

This would allow for a more robust and varied testing of Safari's relative capabilities and shortcomings culminating in a faster, more targeted refinement and development of core features.

Now that being said if I were to have this theoretical build, and use it exclusively I might run into a flash/tabs related bug.   Something like this might happen when I am surfing:

If I am surfing at Site^A and then open a tab and load Flash Site^B, then decide that Flash Site^B is taking to long to load and close the tab, Safari might crash... every single time.

But of course this is all conjecture and speculation since there is no leaked 1.0 beta (v62), and even if there was then I for one would not be running it... exclusively.. and loving every minute of it.  Seriously.   Stop looking at me that way.