It sounds like Vudu are continuing to struggle in the IPTV STB market, as have many others. With the latest announcement from Intel on its embedded TV chips and virtual STB applications like Inuk appearing on the market, it seems that this has always been a market too far.
The cost and intransigence of the major studios has also been a contributory factor. As content wholesalers they - probably rightly - can't see why they should subsidise small startup services against their existing paying client base.
The real trouble is that almost everyone already has some kind of PPV option from their existing service provider, who have both an existing technical and marketing relationship with the viewers out there.
As the UK market shows, incumbency is a powerful ally.