When someone mentions Assassin’s Creed I’d be willing to bet you that you don’t think of Desmond, at least, not instantly. You’re far more likely to think of Ezio, or even Altair, if you’re a fan of the first game.
I love the series, I have played all four of the games and have enjoyed all of them (minus the ending of Revelations, but I won’t ruin it for anyone who hasn’t finished it yet) and, despite looking, I can’t seem to find any plot holes, apart from the fact that Lucy is missing a finger despite Leonardo’s modifications to the hidden blade.
What I can do however is realise that the game doesn’t have a proper main character. Almost all games have main characters, and all of the good ones make sure that they’re, Metal Gear has Solid Snake, Uncharted has Nathan Drake and Red Dead Redemption has John Marston. They are all great games and they all have great characters. Assassin’s Creed has great characters; Ezio and Altair are two of the coolest characters games have ever had but Desmond? Who cares about Desmond? It speaks volumes that his main parts in Revelations aren’t even mandatory, and too be honest, they aren’t even interesting. We know about him and we play as him from time to time but I don’t know a single person who considers him to be the main character and most people simply don’t care about him, they just want to know what happens with Ezio and Altair.
Ubisoft say that the next game will be the end of Desmond’s story but, quite frankly, they will need to do something drastic, something like set the entire game around Desmond, have you play as only Desmond and give little mention to Altair or Ezio, otherwise the game won’t feel like it belongs, because Desmond seems too insignificant, it won’t feel like Assassin’s Creed, it will feel like a spin off, and probably a bad one at that.
Also where is Viddic? The games main villain suffers from many of the same problems as its hero. The first game set him up as your nemesis and it did it fantastically, then he appears for about two minutes at the end of the second one and no one has heard from him since. Will he be in the next game? Has he been up to anything in the time Brotherhood and Revelations have taken place? Is he even still alive? How many people even really remember him? I mentioned him to a friend the other day and it was only then that even realised he’d been missing.