Yes a lot of the LGW services, quite a lot of LCY service are not daily (ANE, UIP, CMF) and much of these wonderful T5 beach destinations are in there. Ditto the ski destinations like FDH. Also the Iberia Express services slowly creeping into T5. Asturias anyone? (Really cheap fares, incidentally). My generally approach is if I have to think what airport code is CMF, it probably won't be daily!
Now the implications is that for weekend and other short trips there can be problems linking up a suitable schedule. I did Bergerac recently:
http://www.flyertalk.com/forum/briti...gerac-egc.html
which is actually do-able, but you do have to watch the timings, particularly given in this case Bergerac is quite dead on a Mondays.
The other implication is that if irrop'd somewhere like this, BA may get lumped with hotel bills for several days if they cancel a service.