On Demand Books has been distributing their POD machine since 2007 but they have not been able to offer much in the way of popular titles. The last time I checked the only major publisher to support the EBM was HarperCollins, and they only release some of their backlist to the platform. The rest of the content came from Google Books (largely PD titles) and Lightning Source, Ingram's own digital (ebooks, POD, etc) distribution service.
I'm still waiting for info on the titles Penguin will make available via the EBM as well as the prices, but as it stands this looks like a very attractive news for current and future Espresso Book Machine. On Demand currently lists 60 Espresso Book Machine locations on their website, a number which will surely grow as more content becomes available.