Beta pet levelling speed

[The Insect Man]

This is assuming that the xp gain in beta is the same as it will be when Cataclysm goes live but:

From level 80 to 81 I was able to level 2 pets from 77-80 without a great deal to spare

From level 81-82 I could happily get three pets from 80-81 with probably enough time for a fourth.

Keeping multiple pets at your level seems relatively easy, but do note:

As Cataclysm quests are overall much more varied and interesting that previous ones (even the superior WOTLK ones) a lot of them don't involve mandatory mob killing, therefore your pet falls behind.

Tradeskill levelling seems a good xp earner but again, this will result in pets losing out xp wise.