The biggest difference is that in RISK you had to control the continent at the start of your turn, while in AA50 the bonus is received at the end of your turn meaning you can acheive the requirements on your turn and then get the bonus before another player interferes. It’s essentially a page pulled directly out of RISK, where you get bonus armies for controlling all the territories in a continent.
The concept of National Objectives seemed familiar, and it took me a while but now I realize why. Scandinavia being split into two, Eastern Europe being re-drawn, and the new Northwest Europe territory will all improve the depth of gameplay in the European theater. The addition of Burma is very exciting to me and has long been needed, as well as the new representation of China. Breaking it into 3 separate panels is perfectly fine by me. The realistic feel, the mix of bright and dark colors, the new blue for the oceans, it all looks great.
The first impression most players will have seeing the game played will be the map, and I think most everyone will agree the map looks gorgeous.