Meh, what I've seen from the game really interested me, videos and such, thought about buying it.
But then, I read that there are certain unlockable upgrades, that make you more effective in combat, be it more damage and precision for your guns by different bullets or some sight, or more firepower and health for tanks you use by some shell or armor upgrade, just as an example.
German:
http://www.gamestar.de/index.cfm?pk=91526&pid=6&b=1&p=1
So actually, when you're new to the game and someone has played it for a few hundreds hours, you'll have a disadvantage and probably loose some fights not just because the other guy plays better, but also because he has a gameaccount with lots of hours that make him stronger..way NOT to go.
The other way around as well of course, I really dislike this.
Oh and wait, upgrades or not, Bad Company 2 contains SecuROM (with activation limit), so as far as I'm concerned, it's epic fail anyways, gg EA, keep your crap, no money from my side.