Whilst it's been common knowledge for a long time that viruses and bacteria may pass on DNA to their host species (the Human Y chromosome is little more than a short stretch of DNA that roughly transcribes to 'hairy, with a cock' strapped onto a whole bunch of parasitic DNA), this is the first time the whole genome of a parasite has been found in it's host.
Obviously, this could allow for large, rapid evolutionary movements for the host. It could become immune to the parasite, freeing up resources and giving it a competitive advantage. It could develop new atrributes. Or it could just die. It'll definitely be interesting to see where this goes.