Some general observations on this.
That ICC is willing to clamp down on blatant violations of the laws, is a positive development.
Does it signify the end of the doosra? I would disagree. If anything it gives the doosra a boost.
There are still bowlers who bowl the doosra without their action ever being called into question. Ashwin for one at the start of the year was using the doosra or the carrom ball, as his stock delivery and the traditional off spinner as a variation, and not once did I hear about any questions raised on his action. Oddly enough, during the recent India-England series, Ashwin hardly bowled the doosra at all. Was this in light of the clampdown that we have seen, or just that he didn't need to use it, I don't know.
Ajanta Mendis is another spinner who has a bag of tricks in his kitty and can bowl every type of delivery. His wikipedia page doesn't mention him having ever been under the scanner for suspect action, despite having a very unorthodox one. So he is another example of a player who can do it within the rules.
Thus Ashwin and Mendis are proof that the doosra can be bowled within the rules. If it was not possible to bowl it within the rules, then one could say, the rules need to be changed. However, with clear examples of bowlers doing it within the rules, there is no place for that argument. If something can be done within the rules, then do it within the rules. The clampdown is positive (I have nothing against Ajmal), and unless there is a clampdown the spinners will keep flouting the rules. With a clampdown the bowlers will be forced to learn do it within the rules. Importantly the younger bowlers will also learn to do it within the rules as they cannot get away with it.