Yes this is just a technology demonstration by ZTE and Openreach, but being able to run 10 Gbps over a PON architecture fibre link shows that there is a long lifespan in the architecture the local loop provider has decided to deploy for its FTTP service.
The demo took place in Cornwall running over the top of an existing 330 Mbps FTTP service that Arcol has in the county. The XGPON standard is still pretty new, with Verizon testing a pre-standard Huawei version on its FiOS service back in 2010.
While a 10 Gbps service for areas with FTTP is some years away, it is very likely that in 2013/2014 we will see trials of a Gigabit service from Openreach. Gigabit fibre services are already available via Openreach, but these are dedicated Ethernet services that include greater commitments to repair faults quickly and usually uncontended bandwidth, thus making them too expensive for the average youtube uploader or SME.