Fall Weather Friends shows us some rivalry between Applejack and Rainbow Dash, which I think the writers really could still expand upon.  This kind of competitive spirit between these two characters could make for some other interesting episodes in the future.

DRWolf Narrator by DavionXY:
http://davionx.deviantart.com/art/DrWolf-Narrator-377863090

All other Characters and Images belong to Hasbro.