I'm still trying to figure out what the heck the KanColle anime is going to be all about...
The first PV
surprised a lot of people with its serious tone. Not to mention it was the first official depiction of what ship girls fighting actually looks like (the game is fairly abstract on this point, battles are mostly represented by icons and such). The undeniably odd visuals aside, personally I actually found the serious tone kind of refreshing. The game has always had serious elements but a lot of the spin-offs emphasize the sillier stuff. Though there have been quite a few doujins and such that have delved into the serious side, with some interesting results.
Now they just recently released a new PV
that appears to be a total 180 in tone. Actually, it appears to basically be Fubuki Ganbarimasu the anime. Perhaps I should clarify, Fubuki Ganbarimasu is one of the first (maybe the first? not sure) official spin-off mangas based on KanColle. It's probably the most well known and popular series at the moment. It's a 4 panel gag manga, though, and I would argue that it doesn't really stand on its own very well. It's more like a supplement to the game, much of the appeal comes from seeing what the characters you know from the game are doing in their downtime. But it's only half the story because that manga never even shows their sorties and stuff.
So anyway, we've got two PVs that appear to be showing very different takes on the same show. I guess maybe they're implying that they'll be doing a bit of both? I don't really know how well it's going to work. This is such an odd property to adapt into an anime yet it has such a large and passionate fanbase there is going to be a lot of complaining no matter what they do.