That is an interesting way of distributing betas. But, wouldn't this cause more harm (bad press) than good? I never really found the distribution of betas that hard (from a tester point-of-view). You don't even have to use that ad hoc app. I tested one beta and all I had to do was load both the beta app and the mobileprovision file onto my iPhone. As a tester, it was very easy from my side. Maybe it is a lot harder from the developer end, idk.
I would imagine that it depends on the company and product.
One time when I was a beta tester for a Newton application, the updates came so often that it created a non-motivational environment if you will. By the time you discovered a bug, confirmed it, and then reported it, the fix may have already been out, but you wouldn't know until after the fact. Hope that makes sense.
Keeping track of the Beta, the bugs and fixes is a developer's function. This definitely takes resources to accomplish if done effectively.