Interesting, I did a bit of further digging. The manager of that research, Dr. Ian Bond at Bristol University is a fairly serious player - his work mostly is in doing clever stuff with composite materials - such as predicting their life and working out how to dispose of it at the end of it's life.
What he seems to be saying in his research is that with primary composite materials it's possible to include either resin or dye within hollow fibres so that if the structure gets damaged it may be possible to either (using the resin) have it self repaired or (using the dye) have it leach colour which indicates BVID (Barely Visible Impact Damage).
Presumably this is a fairly small change to existing composite material processes, hence the proposed 4 years to service - although I'd guess that's probably really "4 years to putting some small non-critical panels on an aeroplane and seeing how it works for a few years" - which would certainly be worth trying to see how it works.
Department of Aerospace Engineering : Multifunctional Fibre Composites: Self-repair is worth a look for some rather more informative words and pictures.
G