First if you already know, im sorry to waste your time. second, this is old news, it's just that some people still don't know so I decided to post.
There were many people got upset because of the ending... I have to say LOL ! watch it more careful... lelouch's not dead. It's not a guess, it's a fact! Firstly, as you all know people who have Geass all have that little purple ish eye thing. nanani does not have that...So we know she doesn't have Geass. How did she get the flashback thing then? If you all still remember from the first season, when C.C. saved Lelouch from Suzaku she touched lancelot and made suzaku getting a flashback, when Lelouch touched C.C. he got a flash back of C.C.'s past. It's a special power of the people holding the C code. yes, Lelouch got the code. Why is C.C. not dead like V.V.? There are two possible explainations. 1. Lelouch got the code from his father, when he killed him. 2. Guess what... There will be a Code Geass movie, so the company can make more money off of it, how can they make money with out C.C. (currently the most popular female char in Code Geass.)
Another evidence would be that at the very end C.C. was talking. Most people would think she is talking to her self, but what's with the paper bird thingy? Remember who made that? Nanani did...Do you think C.C. would bring around something nanani made? The answer is obvious that Lelouch was sitting next to her.
Sorry to waste your time for those of you already know the answer.