http://www.prescriber.org.uk/2006/05/ventodisks-discontinued/ for various commenters complaining that nothing else works.
I am thinking of getting a life-time's supply of the thing I have to prevent attacks on the black market, just in case that gets discontinued.. presumably they will gradually degrade but I suspect they may be better than the alternatives. The point at which I switched to the Becodisks rather than crappy inhalers (even with one of those crappy things to breath the output in from) was the point at which the medicine started to actually work so I am not sure I am willing to take the risk that it gets withdrawn.
There seems to be no sign that they are going to be withdrawn, and there seem to be other dry powder inhalers.