I've noticed clicking the hotbar button bound to a pet no longer unsummons the pet, it now activates the new special pet abilities (which are cool.)
Problem is, for pet-dependent characters, sometimes our pets get left behind when transiting zones. The ability to quickly unsummon/re-summon was very useful.
Now I am logging out and back in whenever my pets don't pass through into the next zone or quest area with me, which gets old fast, and has contributed to a few near-death experiences that would have been easily avoidable.