WHAT WE CAN EXPECT
1. A Much More Detailed Explanation Of What Has Already Been Seen
So far there's been no indication that the extended cut will offer any new game play at all. While Bioware haven't officially said that it will be nothing but cut scenes, until they give an official heads up it's safe to assume the boring. What they have said though, is that this won't actually be a "new" ending. Instead they're delivering something that will offer clarification of the ending scenes so that fans can have a more expanded finale. With word going around that some of the voice actors have gone back into the studio, what we can reasonably hope for are some explanations of why Shep's support team returned to the Normandy, why the Normandy left the battle and what happened afterwards. Best case scenario under these limits would be something similar to the ending sequences from Fallout New Vegas and it's DLC where the players learns about the long term consequences of their actions both great and small but with fluid animation as opposed to still shots with voice over.