It's super-liberating as a creator to be able to try wild stuff. The other angle is that there's always the possibility of changing the time period. You can keep the same core but because you've change the setting you can do things like have firearms, have Leonardo Da Vinci.
Although the franchise is in a way stuck with the present - which is the final card that will always be there - other than that there are limitless possibilities with the brand and we understood what Assassin's Creed was while making AC2 - we said 'this is it'.
With AC1 it was an unsure experiment, from an outsider point of view people say it was a sure shot but from inside it wasn't the same, it was walking in the dark and opening doors to see where they lead. With AC2, especially in the last six months we realised 'this is it', captured a genie and put it in a bottle.
For Brotherhood we've got that knowledge and starting to master the language of Assassin's Creed. There are a lot of possibilities.