As I understand it there's not much 'allegedly' about the whole thing. It was designed and put together in 18 months and it's the first of its kind so it is most likely to have some problems. Read about the errors and problems in the first iPhone demo and then reflect on iPhone sales since then.
As for He availability, there are quite a few other uses for it and I was at a talk given by the Skylon people who use Helium as the heat transfer fluid from the fuel to the heat exchanger that cools incoming air. You don't want to put hydrogen through metal pipes because it makes them brittle so helium is used in a loop instead. One problem is that the system has to dump some of that Helium at one point in the flight to prevent some sort of overexpansion problem or other. Their take on it (apart from there being less desirable design alternatives) was that there are other sources of Helium that are not being tapped at the moment and that attractive prices would no doubt encourage people to bring these things online. Who knows?
I certainly haven't seen a very informative list of sources and potential production. I've also no notion of the quantity being used for cryogenics vs the amount used in Airships but presumably liquid helium is much denser than the gas so it could be a relatively large amount. So I don't feel like panicking based on so little information.
I did find this on wikipedia which suggests that we have a lot more problems with other uses of Helium than airships, perhaps:
http://upload.wikimedia.org/wikipedi...eChart1996.jpg
As for "it will run out eventually"....well I'm sure that we'll use it as a reason for mining in space.