This is a funny discussion.
Unlike most of you here I'm not sure this Cernosek issue is as big of a deal one way or another. In fact I'm more worried about someone else: that British/Canadian woman that WTA decided to assign to Petra - what is her deal? I hope Petra is not paying her money cuz I don't see too much of a change in Petra's English or any other proficiencies that justifies the hiring of an expensive personal assistant. It looks like Petra's capacity to present herself in interviews and the like is developing at the same rate as it would under any circumstances.
So if Petra is paying that woman lots of money then it's a waste and she should be fired (let her stick around only if WTA is covering the cost
Why would you be worried about Katie? You think she's a spy or something?
Don't worry. I'm sure Petra pays (if she does any) less money to this Katie woman, than she does to Mr. Cernosek.
And I'm not sure if you were being humorous, but it's pretty clear why people here are up in arms (along with it being the off season): Cernosek appears to have a lot of control, conflicts of interest, personell selections and revenue streams involving/over Petra.
These are many of reasons why people switch their management, Agents, coaches, etc., all the time (especially when it affects their tennis, control or finances). Ultimately, we care more about the tennis (though some care about Petra's well being as well). Hope your joking.
PS: And leave Katie alone. She served her purpose already. Didn't Petra credit her with winning her two North American hardcourt tournaments?