BETA can be release on 2nd or maybe on 30th of September for example.
For the impatient players like me is a huge difference (the whole month) Oo - That is way, I would like to know as well to prepare myself mentally for specific date LOL.
Yeah sure, I get that. You have to realize though, they don't want to give a specific release date simply because they are not sure when they will have a beta client ready to release to the public.
To give you an example, if they said the following: "Ok guys, we'll start sending out invites on 10th of September" and after stating that some small issue comes up that prevents them from meeting that deadline - fans would eat them alive.
I said it before and I'll say it again. 3 month long wait since the game's announcement is really, really short if you put things into perspective. Just be patient.