i don't think kallis has surpassed sobers. everyone still talks of sobers as the greatest allrounder of all time, kallis is a current player if people thought he was near sobers of surpassing him i'm sure we would be hearing a lot more comparisons between them.
stats wise, kallis is as good or maybe even slightly better but factor in that sobers also bowled spin wchih would have pushed his average down and he might have slightly better stats than kallis.
but i reckon if you ask people who have seen both bowl they'll probably consider sobers the better bowler or at least better pacer. and batting wise even though kallis is consistent he has a reputation for being a slow poke (even though when he times the ball perfectly it looks sublime) whereas sobers has more of a reputation for flare.
now as far as shakib goes as has been said bowling wise he seems better, batting wise he has a long way to go. but i'd wonder who is considered the best spin allrounder of all time? shakib might already be pretty close to the top of those ranks, obviously to stay their he needs to continue doing it because longevity is a factor for greats.
All Time Test XI: 1 Hobbs 2 B.Richards 3 Bradman 4 Pollock 5 V.Richards 6 Sobers 7 Gilchrist 8 Procter 9 Miller 10 Marshall 11 Warne