The biggest reveal was the phrase "Max Players: 32," as shown in the image to the right, basically revealing there will be at least two playable game-types supporting 32 players--the first being Team Deathmatch, and the second being the new "Bomb" mode.
SFX-360 also mentioned that Modern Warfare 3 will launch with 13 maps. Unfortunately, a snapshot of the map listing wasn't taken, and with the video having been taken down, there's no proof to support this claim.
Do keep in mind that this all comes from an event that hasn't even started yet. So, while the leaks look and sound convincing, they should still sit in the rumor mill.