Scot Rail have announced that their trains will now carry advertising on the outside. They will become large mobile billboards. This should subsidise travel fares but is more likely to increase profits. The news article is below.
Livery Wrapping for trains
One concern for the modeller could be that new models of trains which have advertising may cost more as a royalty may have to be paid to the advertiser. This doesn't seem to have had a big effect as many modern Continental models have advertising and it doesn't seem to have affected them.
It may add variety and colour to some locos however it may do the opposite as some have good colour schemes at the moment. Can you imagine DMU's with Burger King and KFC on the sides?
Personally I liked the old whoosh logo and would like to see it's return.