Here's what's been done to pets and signatures:
1) signatures now start right after the text of your post, so there's a lot less scrolling
2) pets are now located inside the same space as signatures so they have more horizontal room to display, and cause less scrolling.
what this means is the following
A) if you did not configure a signature for yourself (left the box blank) your pets will not show up for anyone within posts.
B) if you disabled the viewing of signatures, you will not see anyone's pets within posts.
C) Pets on your profile page still show up how they always have
D) Even though signatures and pets are now in the same area, they are still technically 2 separate entities, so as far as I'm concerned the current signature rules still apply. The signature option to outline a red box around the maximum signature size can help you get a visual of how that works.