I'm quite disappointed.
I'm glad they chose a side instead of that weird mix of steampunk and carnival, it seems they fixed themselves on the carnival theme.
Nevertheless, It's a shame they followed the easy road of having the exact same skins for the zeds (redone obviously,but still...). I would have prefered a whole other theme after having the sideshow for years in KF1.
Not only that,but I would have LOVED a new character unlockable by achievements means. And not those horrendous cosmetics that I'll never use anyway.
But hey...At least the map looks awesome! And the trailer was great too.
(As for the weekly challenge, it reminds me a bit of the "mutations" from L4D2... We'll see how it goes,but that could be very very fun)