You can find loads of information on this subject just by searching this forum with the word 'outdated'. Anyhow, the symptoms of ageing is increased base+fog and some loss of film speed. The ageing process is different for different films, manufacturers etc. Your test pic. looks real nice, so there is probably many years still in it.
I have a box of Super-XX sheets which is outdated since the 70-ies, and while it has lost some effective film speed, it still have relatively low base+fog. But on the other hand I also have some TMax 400 which was dated 2002 which have built up quite a severe base+fog.
You can do something in the developing, like choosing the right developer and as a last resort you could spike the developer with some bensotriasole (sp?) which should help preventing b+f. Again, there is plenty of information on the subject available with a simple search.
//Björn