Ow, forgot to mention, but some areas in the Pacific have changed a little of their shape, the most notorious being the East-Indies (it is placed a little more to the South-West now). The changes are for better usage of available map space (OKS, WPO, NPO, SUL, BOR and IJS are a bit bigger now, and 20 pixels are added to Csu and Mex), and correct borders of the American region.
These changes are not huge, but might be a source of confusion. To avoid this, make sure both your and your opponents AA50 modules are up to date ;) Also, I’m not planning on any other territory changes in the near future, to ensure compatibility between the module versions.
But most importantly: have fun :)