Blizzard has integrated the features of many current add-ons into the pet battle UI for patch 5.1. The journal, wild pet tooltips, and battle UI now display information making it easier to choose which pets to capture and which to kill.
During battle, the quality of the pet is shown in the color of the opponent creature's name as well as the border of the icon. This renders Pet Battle Glow unnecessary.
Mousing over a pet in the wild now shows how many of that creature you have collected, if any. It does not show what the highest quality of that particular pet you own, however. So the Pet Caught add-on will still give more information than the new UI.
Mousing over the opponent creature during the battle will also display how many of the pets you own, but again, not their qualities.
More changes are after the break.