A TV special about the show was broadcast on Monday night. You can find it on Nico Nico Douga
here.
Release date for the actual first episode is now 23 May.
EDIT: Interesting TV special. Lots of interview with the director, and with some of the staff, and with Makino Yui, Aizawa Michiru, and Saitou Momoko, the stars. But also with Hirano Aya, who has a secondary role as Femina, a "big sister" character (I had no idea).
The physics and biology look pretty weird and interesting. Did I see the characters floating through each other? They are a new type of humans who can live in outer space, it appears.... Linda Nagata's novel
Vast did that more convincingly, with scales for skin, but this is maybe more visually appealing, lol.
A show that is almost all 3DCG will take some getting used to. Like watching a high-grade Hatsune Miku video that's 22 minutes long. Some great explosions, but the movements of the girls will take the getting used to.
Everyone seems to be approaching the show seriously, with good ideas about the characters, and the comic is serialized in Dengeki Daioh. I thought the delay from December was because of production problems, but maybe they were lining up publicity elements, in the form of Aya and Daioh.
The nicovideo comment stream was surprisingly positive, it seemed to me. Maybe that's partly because the show could be subtitled "3DCG super-lolis save the human race."