NOTE - if you don't want to know stuff about multiplayer, don't read the diary :)
I was originally going to Type all of the info I knew out, but that would take too long. I'll post a couple highlights, then some links.
• Secondary weapons can now include shotguns, sub machine guns, and grenade/rocket launchers as well as the basic pistols
• Shotguns and sniper rifles now can use suppressors
• There’s a first tier perk called Bling that allows you to use double attachments
• Attachment functions have been extended. For example, double tap is now an attachment, as well as extended magazine
• Perks are now upgradable. For example, If you get 1000 kills with stopping power, you unlock Stopping Power Pro, which does even more damage
• There are 9 Killstreak rewards, ranging from 3 to 11 kills required to unlock
• A new option for special grenades “tactical insertion” (lol) allows you to throw a marker-grenade to your desired spawn location. When you die, you will respawn at the location of the grenade.
• Death streaks. If you’re killed 4 times in a row by one person, you can now have the option to use their class for the remainder of the round. This should balance out the game for newbies a little.
For way more, check out impressions on various news sites.
The IW forums are down right now, but there's a lot of info available there too
Some pics
