I was on that flight tonight, the BBC news website gives a fairly accurate account of what happened.
I didn't notice anything was unusual until we were on finals and it was clear we were going into STN. I didn't see the Typhoons (I was fairly near the front though and not in a window seat), although I do understand they were following us, we were in IMC until pretty late into the approach.
On landing my first thought was it was a weather diversion, as there were a few gusts at Luton but when we taxied to the north side I realised something was not quite right.
The pilot came on the intercom and made reference to an un identified threat against the aircraft. I've got to say his communications and manner throughout were excellent.
The rest is as reported in the media, the incident was judged not to be a threat and we were on our way to Luton just after 8, taking 16 mins to do the quick hop.