World class, in my opinion, means that for a period of at least three years you would have been mentioned in dispatches for a "planet Earth" Touring party - so for current players, you'd apply the epithet to maybe:
Batsmen: Sangakkara, Clarke, Amla, De Villiers, Younus Khan, Williamson, McCullum, Pietersen, Warner
All Rounders: hmmm....
Spinners: Herath, Ajmal (if you "allow" for the elbow")
Seamers: Steyn, Morkel, Johnson, Harris, Anderson, Boult
So, not many....
Appreciate in this that there are a few recent retirees who would have made the list - Smith, Kallis, Swann, Tendulkar, Hussey - but its still a rarified list.