I think he should retire NOW. He is at the top of the glory by winning world cup, has 300+ wickets in tests. He is arguably the best leg spinner we have seen.
People are asking him to continue. But it is better to retire when people ask u to stay than when u r kicked out.
Walsh will make it because Akram's health is not fit to last much longer... although I'd love to see him get the most.
Warne, he's a amazing spinner, but that Sri Lankan Muttiah Muralitharan, who is a spinner, keeps getting wickets and wickets in county cricket.. but can't seem to get it in International..
Let's see what will happen..