IMO it was pretty long overdue. He was atleast 3 years too late to come to this decision.
All in all a fine ODI bowler, upto the starting years of this decade. Thereafter, he was quite mediocre, be it bowling, batting or fielding. His ODI average too suffered a lot to due to his decision to drag on his ODI career.
Had he quit ODI cricket after WC'03 a la Warne, he'd've added quite a few more test wickets to his already impressive test wickets tally.