In Blizzard's latest "Ask the Devs" segment, developers covered questions regarding achievements. Luckily for us, the question on every pet collector's mind, 'will there be a companion reward for the upcoming 4.1 pet achievements?' was answered!
A: Patch 4.1 has achievements for 100 and 125 companions. Those particular achievements don’t reward pets, but we’ll probably do another reward at some tier in the future, perhaps 150 or 200 pets.
While it's disappointing that there won't be any new pets tied with the 100 and 125 pet achievements, it's great to hear that there are indeed plans for future pet achievement tiers with possible rewards.