After that it gets a bit confusing...some years they try new ads, sometimes they re-use the trucks, this year they're doing both.
I think they've used both the trucks and a new ad for the past few years, with the version of the trucks that aired last night being the one they introduced last year.
http://www.youtube.com/watch?v=4TMwBFK2qHI
Seems they've changed the instrumentals, with slightly lower pitch vocals and an additional line to extend them to the end of the ad. I wonder whether this is a later edit, or if this is a version for the States and we're getting the version posted on the first page. Personally I prefer the first version we saw.
I like John Lewis' adverts, they have a certain quality feel to them, and the soundtrack choices are pretty good.
I agree with you there, they have a good feel to them without having to resort to the visual effects some other ads have. Their soundtrack choices do seem to go down well, Ellie Goulding is now #4 on iTunes, and I remember the soundtrack to the previous ad doing well in the charts and gaining radio airplay also.