anton has a date for the site(here it is

[Raw Kryptonite]

DLC = downloadable content

Sometimes free, but usually there's a charge. Might be missions, campaigns, planes etc. It's annoying to have to pay for these things, but at the same time, after a game comes out people are usually clamoring for it.
If it's actual NEW content, I'm glad to buy it. If it's paying just to unlock something that was already on the disc but you didn't have access to w/o paying more, that's a different situation. Sucker or not, I'd still buy whatever it is. Just no other games like this out there or on the horizon, so they've got me.