Nothing new here, move along now.
I don't think this is a particularly new model. Companies like Martin Dawes have been offering this for a while.
As the article points out, there are several levels of MVNO -- Virgin do pretty much everything above the network -- own CRM systems, IVRs etc.; while others do simply 'rebrand'.
I think there is mileage in the MVNO idea though -- it just has to be done well. Where an organisation is already trusted, they can bring a lot of good will to the offering -- this is where Blyk failed (innovative offering, no one had heard of them), but Tesco succeed (fairly standard offering, but a brand people -- rightly or wrongly -- trust). MVNOs can bring in other factors too -- cross selling into their normal business (Sainsbury's giving double Nectar points if you top-up your Sainsbury's mobile at a Sainsbury's shop is a good example -- gets you into the shop, you might buy a few veg!).
On the other hand, there's no point in slapping any old brand on top of a completely undifferentiated service. What are you offering consumers/businesses that no-one else can?
So, that's the key (and you can have this consultancy magic for free): come in with a well known and trusted brand, and offer something unique to you, that no-one else can easily copy.
I'll drink to that.