Thanks for coming back to me. My problem is that when I load 1.8, although the opening screen is different from 1.7, I get exactly the same style industries, vehicles, etc. as with 1.7. I know there are changes eg. to farms, ports, loading terminals etc. and that's what I'm trying to get to.
Defaults did not change at all. Concerning a particular NewGRF: the "big" ones (FIRS, ECS, TAI) have usually good changelogs which can even be viewed ingame from the grf config additional to their respective websites.
As it's virtually impossible to summarize "everything what changed in two years with all possible NewGRFs", I suggest that you ask questions about those which you actually use and interest you (we cannot know which those are)