Wikia are due to update the appearance of the top navigation and article header areas sometime during the week commencing June 12th.
I would say that overall the new headers are an improvement and look a lot more modern. However, I do not like how a wiki's name is now stated next to its logo. Also Wikia's announcement blog post for this states:
"Outside of the Theme Designer, we've decided that, in order to maintain a consistently modern look across FANDOM, we won't be allowing most forms of CSS/JS customisation of the header"
While I don't anticipate us needing any custom CSS in the new headers, I am concerned that this move is just one step closer to eventually completely banning custom CSS on Wikia.