The next Gears of War 2 XP event is actually based on you and how many other people follow Rod Fergusson, Executive Producer of the Gears of War franchise. The event is not currently set with a date yet and neither is the amount of the experience multiplier. Here is what he stated about the event that will most likely start around the same time as the San Diego Comic Con event which will begin on the 22nd of July.
“Ok, here’s my bribe. The SDCC XP event will be # of my followers divided by 500. So 4000 followers means 8x XP”, says Fergusson’s (aka GearsViking) tweet.
You might very well be able to receive x20 XP online or even more in Gears of War 2 for this next event. It all depends on you so if you want some crazy XP in Gears 2 to reach that top rank of 100, then get to Twitter and follow GearsViking.