By now it is known that that Chappell and Frazer are assisting the Aussies in the upcoming series, first by helping secure variety of facilities at the RCA for which he is the head coach, and then by providing tips about the Indian players. Frankly, I don't think the second issue will matter. Most players if astute, should know enough about each other (including the strengths and weaknesses) from the IPL days and having played each other so often. And maybe he will bring the same luck and success to the Aussie team that he had when he was the coach of India :)
However, I find a couple of issues baffling. Can you imagine a consultant at a subsidiary of Pepsi, taking up an assignment at Coca Cola to help develop a counter-strategy against Pepsi? His prior stint as the India's coach notwithstanding, as currently the head coach at RCA there does seem to be some direct conflict of interest. He is also the head coach of the Brisbane Cricket Academy and now the assistant coach for Australia. Shouldn't the BCCI ensure that contract of coaches, anticipates and deals with such issues before they become a problem?
Second is the issue of head coaches switching to other countries after their tenure. Again, while I cannot imagine Bill Gates working at Apple, I don't see how coaches can be prevented from taking up other assignments once a tenure is complete. But maybe a clause in their contract would atleast stop them from publishing a book after their tenure.
And lastly, Chappell's comment on Yuvi "I made him the player he is now". Considering Yuvraj's current test status and form against spin bowling, what is he taking credit for? If Yuvraj had learnt something from him, would it simply be "un-learnt" when a coach quits?