Paul
A lot of modern aircraft, and certainly longhaul aircraft, will have a moving map display which will show you where you are, where you have been, present altitude, temperature and groundspeed etc. It will also show you time at destination and when you will land.
What more can the pilot advise other than the expected weather?
Add to that the fact that on a longhaul flight, making a cabin announcement will interupt the film and that people will want to sleep at different times and I firmly believe that silence from everyone on board is the best solution.
On shorthaul without moving maps then maybe a quick mid flight update, but it's not even then really necessary if you tell them enough before the flight departs, just an update 20 minutes out from landing.
All imho [edited for speeling]