Update: The Bookseller reports that this deal only includes 5,000 titles, and that it won't take effect until February.
AudioGo was one the leading audiobook publisher in the UK. Originally known as BBC Audiobooks, it was spun off in 2010 and sold to a group of private investors and venture capitalists. AudioGo currently has a catalog of over 10,000 titles, including audiobooks from leading authors like Dick Francis, J.K.Rowling, Stephen King, and more.
The Bath-based firm went bust after financial irregularities were uncovered, resulting in the closure of its UK offices and the sale of its US operations. The US operations were sold to Downpour, an audiobook retailer that AudioGo acquired in late 2012. Downpour also got the US rights to the AudioGo catalog, which suggests that Amazon only has the UK (and possibly global) rights.
At this point all we know is that Amazon has acquired the catalog; there is no info on whether Amazon will also acquire the business, records, or production facilities.
Amazon already owns a couple audiobook publishers here in the US (Audible and Brilliance Audio), but I don't know about the UK. There is an Audible UK, but there's no sign that it produces its own content. A more general acquisition could suit Amazon's interests.
Amazon bought Audible in 2008 for $300 million. It is the world’s largest producer and retailer of audiobooks and the exclusive supplier of audiobooks in iTunes.