Par contre je peux te dire qu'il y aura une demo 
MSXBOX World had an interview with Battlefield 3's executive producer, Patrick Bach. Among the questions asked, was whether or not there'd be a BF3 demo. The answer was simply, yes. Yes, there will be a Battlefield 3 demo. No details as to what the demo will include other than it will be released before the games release in November. It's not known whether or not the demo will be released on Xbox 360, PS3, PC or all three. Nor do we know if it will be single-player or multi-player. ATFB raised a valid point for a multi-player demo, "With the game being multiplayer centric, and looking to entice the gazillion of annual Call of Duty buyers into something new, our money is on multiplayer."
When could we expect the demo? Probably in the early/mid fall 2011 range. This would be near BF3's release, but after the beta adjustments and feedback have been made. We believe there's a good possibility the Battlefield 3 demo will be released on all three platforms and will be multi-player.
Je parle pas de la beta hein 