I woudn't worry about it, there are always people who get angry when others do this kind of thing, it got especially heated with the leaked Safari versions.
My opinion is if you are registered with MacRumors, you really shouldn't complain to people about it. Rumors do more damage to Apple that people installing beta software, and MacRumors often gives links to articles and threads (such as the ThinkSecret ones) detailing Panther. Also it's like arguing about the death penalty, abortion, etc, everyone gets angry and no-one gets anywhere.
Now I have a question for the Jaguar beta testers;
I had only just found macrumors as Jaguar was in testing, maybe 2 months before it went GM, therefore I don't know how many builds there were, can someone tell me? Also were these builds released on CD?
AppleMatt