Just wanted to add my $0.02 on the discussion.
Battlefield and CoD games cannot be compared in terms of gameplay. They are almost entirely different genres if you think about it.
Battlefield focuses on a more war-like experience, you work as a team and have various roles for supporting one another.
Whereas CoD games essentially let us play as John Mcclane but with a bigger choice of weapons.

Not saying it's a bad thing, but it's not the same at all.
In response to a few comments/questions raised in this topic:
- Prone - This won't be added as it slows down gameplay and encourages camping. Unlike CoD, a sniper isn't a lone-ranger fighting for himself, he is supposed to follow the squad (at a distance of course) and provide support.
- Damage - Play hardcore mode, simple as that. Health is reduced, making 1 shot kills possible with the sniper. (not that it's actually more realistic, just a more deadly style of gameplay when cover is actually useful and not an obstacle)
- Graphics - As someone else pointed out, the high-end graphics are unable to be seen yet, so do not judge the graphics based solely on the beta.
- Realism - Neither game even comes close to being realistic. If you want realism, try playing OFP (original..not dragon rising) or one of the ArmA games... I could rant for hours on how much more realistic they are when compared to the other FPS' out there, but i won't waste your time.
So what i'm trying to say is, these games are not in competition with one another. The fans want different things.
If you want to jump into a game and start killing instantly, and don't want to have to utilise teamwork, stick with CoD.
If you've got a group of friends and like working as a team, stick with Battlefield.
Personally i'm not a huge fan of either of these franchises. I've been a "mil-sim" player for too long, and the slower pace makes me almost useless in these crazy fast-paced shooters.

That being said, it's still fun to jump in occasionally and give it a go.