Sorry to disappoint - but I haven't noticed any extra increase recently in UKP251/252. Well - no more since 9/11.
Also - the military stuff is mostly on jollies. The AAC/RAF/and Navy are always going through the zone. After all - a trip on the Thames at low level is far more fun (and probably harder to fly accurately) than OCK-BIG-QE2! It is used as part of nav training by the Shawbury lot frequiently - routing through busy exacting routes is quite a challenge if not done before.
Maybe you are being watched, STS!?!?!