There never has been much of a tradition in some countries for a large pool of spin bowlers. Newzealand, South Africa, West Indies are prime examples.
Australia, India, Pakistan have been the countries with a strong tradition for long. England lost wrist spinners long back but continued with finger spin and even that has almost vanished as far as real quality is concerned for many years now. Sri Lanka has not had any really great proponents except the incomparable Murali.
So one would say that of late the spin pool in the world has been richer than poorer compared to, say, twenty years ago. Vetori brings a much better option than Newzealand has had for so very long.
Having said that, retirement of Murali and Kumble which must come following Warney will naturally crate a HUGE void. It would have been difficult to fill in the best of times.
I think the biggest concern is that India is not showing any great young talent emerging. This is not surprising, however. The emphasis on one day cricket and the sudden craze/effort for 'creating' faster bowlers (which is great were it not so half-hearted and disjointed). India needs a spin bowler academy as badly as it needs a fast bowlers one but the latter has been in existence for nearly two decades now and the other continues to be on the drawing board. This inspite of having available for guidance three of the greatest spinners in living memory.
Australia seems to be the only country with a balanced approach and hence results in this regard.
Other than that one is not sooo pessimistic. I just hope Monty meets with some big success on a consistent basis if we have to see the beginning of a revival in England.
A disappointment is the continued neglect of spinners as an attacking as well as defensive option in limited overs game by so many countries. I suspect, England, NZLand and South Africa suffer from this besides Windies who have a greater dearth.
A sidelight but strange observation is the relatively poor standards of fielding amongst bowlers in general and spinners in particular. Why do they appear so slow and laid back on the field? The exceptions are, by and large though not always, those who are not masters of the art of spin. Is it true or am I imagining things ?