Bear in mind that these are only random tidbits and don`t actually reveal anything concrete about the plot.

Characters:
Plush toys of the three main penguins were showed. I didn’t get screen caps from them, unfortunately.They are very similar, in general, the only difference is that Himari has a bow on her head and her eyelashes ( just small ticks on top of her eyes), while Shouma has a band-aid on the right side of his face under the beak and typical “angry” eyebrows.

The human character designs were just showed in a slide show from an I-pad 2 from pretty far away, so there’s not much to be said about it. Shouma’s hair is bluish, Kanba’s looks light brown. Himari seems to have a hime cut. There were several other characters as well but there’s no way of knowing who they are.

They also said there are other non-human characters.

Story/Setting:
Ikuhara said the story begins with the murder of penguin number 0 (incidentally, Shouma, Kanba and Himari are respectively number 1,2 and 3)

The penguins are in some kind of association.

Yutaka’s character is completely different from Satou from Welcome to the NHK (one of his previous roles).
When asked about the genre of the anime, Ikuhara , after thinking about it, said “Mistery” and then completed “Penguin Mystery”.

The penguins in the series are about the same size as the plush toys.

Humans “pilot” those penguins. Some guy on 2ch stated Ikuhara said they pilot from inside the penguins somehow, I personally don’t remember him being that specific.

Many scenes take place in subway/trains . A red train is also mentioned to appear.

The penguins are often seen eating things that aren’t supposed to be eaten, for instance train passes.

There’s some sort of Queen Penguin on the station.

The symbols on the bottom of the official web site have some hidden meaning.

Speculation: One of the symbols on the bottom of the site says 95. The show mentions a red train, and one such train is associated with the Marunouchi station. Because of that, some speculate that the series might be related to or at least reference the sarin terrorist attacks that happened in the Marunouchi station in 1995.

One of the lines from one of the CM’s, “invisible existence” is strongly associated with Seito Sakakibara, who killed two children in 1997.

Voice actors:
Koizumi Yutaka and Arakawa Miho are confirmed to be major characters. Yutaka is probably not one of the 3 main ones though.

They also mentioned Iwasaki Ai will be the voice of several non human characters.

Kanba’s VA is someone REALLY famous.

This is mostly speculation, but during the stream they said that you might find out who it is if you looked at the history of Takahashi’s blog. In one post, she said “I just shook hands with Gian!” From there it’s being speculated that the voice actor is Kimura Subaru (Gian’s voice actor in Doraemon).

Even more farfetched: Kimura made a twitter post saying “The macaron Noto gave me was delicious.” And then less than two hours later, he made another post saying he had just finished an after recording. So IF he really is in this show, and he was with Mamiko Noto during an after recording, that could mean that she’s also involved.

Some people have stated that the voice in the male voice in the 2nd CM belongs to Kimura Youhei.

The cast will be announced next week in a magazine (most likely comes out Friday).

Book:
The first of the three books comes out on the 4th of July.
The first part covers all the episodes completed until now (probably 8 or 9 eps).
The anime supposedly isn’t easy to follow.
The book will be hard cover with no insert images. The cover illustration is by Hoshino Lilly.
Some lines are said by different characters in the novel and the anime.
Yutaka’s character’s hair color may be different from the anime.
Takahashi is currently writing the beginning of the second novel.
The last book will have lots of differences from the anime.
It’s not a very cheerful book (might apply to the anime as well).
There are dancing and singing scenes in the first half of the anime, but in the book these scenes will be replaced with different scenes that would be happening simultaneously.

Woot~ wooot! Това ще е голяма зарибявка с тоя пингвин. Определено ще се гледа. Прилича ми на някаква комедия в стил dumb acting, предполагам. Ще е яко.