In My Little Pony G5, many years have passed since G4 and it looks like both Twilight Sparkle and Opaline have had played key roles in the downfall of Ancient Equestria.
What is not clear is how Opaline became Princess and what caused her to turn away from the Magic of Friendship altogether. 
The Brony fandom misses Tara Strong deeply as Twilight Sparkle and it would be cool to give her a proper goodbye before she moves onto voice acting more cartoons. 
Picture credit goes to megatronsthiccthighs