Considering the amount of progress they've made in the past month and what they have left to do. Beta will probably be in September if I had to guess. Although I get the feeling the beta is just gonna be a couple weeks of publically playtesting the finished product to find and squash any remaining bugs for the official release. I doubt it'll be a 2 month long beta or something.
It has been stated already that there will not be another stretch goal, simply because everything on their wishlist that they could possibly throw out there would end up acting as a hindrance to development of the actual game, rather than a worthwhile incentive to buy more copies. That said, why do you care if other people buy the game, why dont you focus on grabbing all the copies before some other yokel comes by and takes one?
Woot some mushrooms for the Florans..., how about some ssky planets for the Avians Wish you guys goodluck at i49, see you on a livestream !
That would be a pretty damn patronizing thing to do. I would feel like a baby if they did that. "Here you go, little beta-testers, we left some bugs here and there so that you'd feel useful. And we even turned off monsters so that you won't have any trouble finding them." There will be PLENTY of bugs for us to find dude.
*CRY'S* WHY, WHY MUST I49 BE ON TH OTHER SIDE OF BIRMINGHAM ITS TO FAR TO GO . I SOOO wish i could attend to meet you and play sb however due to the playable state its in for i49 i predict beta will be announced there it seems to fit
Best of luck to the entire team at i49, I'm sure the build for the game will look great and excite even more people to want to play Starbound!