I would not think the transfers would work anymore. As far as I know, when you transfer, it's only an option if the name and CC on the two accounts match. Before everything was tied to battle net, this wasn't the case. But, you also didn't get all the pet dongles in the mail. A friend of mine had the original CE on one account and he didn't have multiple dongles to move. There was a small window before they did the Battle Net thing where he had multiples and he could transfer. He did move a set over to his 2nd account. We had talked about trying to trade ce pets, I had the Netherwhelp. But at the time, we'd have had to buy an account then change the name on it then when he called, they said they'd make him wait 3 months after the update before he could transfer. Old character transfers were much more limited. So, we never went through with it.
I also moved the netherwhelp over to my nephews accounts that I was paying for at the time. Before, they had a dongle they could trade behind characters of the same faction. Now, they have the pet account-wide, which is quite nice. But, you don't even get the boa dongles in the mail like you used to. So I presume new CE pets like the D3 Fetish Shaman or Baneling, it won't be possible to pull that trick.