He's still one of the best batsmen in Australia, as his success in the Pura Cup (or whatever they call the Sheffield Shield now) shows. It isn't like the 90s where they were a string of very good bats piling up runs -- no one is scoring runs, and he will be a darn sight better than anyone not named Clarke..
It is a step backward, but if he is hungry, why not?
Maybe Ponting can go play for an English county team (I'm sure someone will sign him) as soon at the IPL is done, score runs by the bucketful, and slide into the Aussie side by the 3rd Test which should be around late July, giving him a good 2 months to get completely used to English conditions.
Bharat