wow.com reports that there was a change to the murkimus companion with this patch. murkimus was the 2009 pet reward for participating in the arena tournie. it was a short-lived and separate event from the live servers, and you had to pay about $25 US to join.
with the change all characters past and future, on an account that met all requirements to receive murkimus, will now receive the pet.
it's not a huge change but i'm sure it will make collectors with this companion very happy. a change like this would be the equivalent of any noncombat pet suddenly being available to all your toons on your account. blizzard's making the right move here, especially since there was a real life fee in order to get the pet. now if only they would change the TCG pets too.... ;)
do i own a murkimus? unfortunately i don't as i was too poor and uninterested in PVP at the time. oh well. can't win them all :P