The responds from those from the special screening showed that the people who went to the Kancolle anime special screening were pleased with what they showed. This suggest that the first episode shows potential promise and may become a big hit.
Most of the anime focuses on introducing Fubuki along with some of the Kanmusus she meets as well as getting acquainted with Mitsuki and Yuudachi.
So far we got to see the following Kanmusus appear within Episode 1's special preview:
Fubuki, Mutsuki, Yuudachi, Akagi, Kaga, Nagato, Mutsu, Kongou, Hiei, Haruna, Kirishima, Shoukaku, Kuma, Tama, Sendai, Jintsuu, Naka, Tone, Atago, Shimakaze, Akatsuki, Hibiki, Ikazuchi, Inazuma, Mogami, Yuubari, Kitakami, Ooi, Mamiya, Ooyodo, Asashio, Oshio, Michishio, Shiratsuyu, Shigure, Murasame, Kagerou, Samidare, Hiryuu, and Souryuu.
Besides the basic stuff we also get to see several references in play here...
For instance there's already an onsen scene! This serves as the DOCKING area! Akagi's resting in the onsen there's a timer above her.... set for....16 hours.
Also a small battle does take place late in the episode. Kanmusus seem to get thier equipment from some mechanize device which seem to store thier turrents and ship equipment in some underwater cave which get pulled up on some chains and then latch on to thier Kanmusus.
Besides that we watch as the Kanmusus go out and battle against a few Abyssal destoyers and get to see a nice introduction at the very least at how the battles translate based on the anime (which turned out pretty good to the views)
The transition between 2D to 3D animation wasn't all that bad either from what people saw and basiclly the overall conclusion is the first episode had a great start for the anime.... But I'm only mentioning what people have said, so there's probably more to this if we watch the anime when it airs later starting on January 8th.