They didn't completely nerf it. Steamrolling low lvl pets gives very little exp, but I'm still getting 90k+ on my 85 pally through pvp pet battles (both sides using 2 25s and a 1+).
Edit: Got the same exp as pvp battles as I did fighting a group of pets in Vale with 3 25s. My guess is they simply changed it to scale with what lvl pets you're fighting, or perhaps that was the original intention and it somehow slipped past them when implemented.
XI Wiki


