Only got a couple of hours play so far but I am far from disappointed with it.
The Da Vinci Edition says it includes:
1 Single player story mission "The Da Vinci Disappearance".
2 Additional solo maps "Trajan Market and The Aqueducts".
Multiplayer extras: "1 Map + 6 Characters + 2 New Modes".
To my pleasant surprise it also seems to include "The Drachen Armour" even though there's no mention of it.
The graphics are amazing, a fair step up from AC 2.
The story follows directly from AC 2 much like it did after AC 1 which is great.
Gameplay is still as nice nothing has really changed so you feel right at home with the controls etc.
The fights seem to have been improved with new moves which is really fun and adds a new aspect to the game.
All in all the game seems as awesome as its predecesors!