In celebration of the 4th of July, Gears of War 2 will be infested with even more tickers (pictured). From a forum post by Gears producer Rod Fergusson:

...to give a little extra bang to Horde we're bringing the Ticker squad (a group of Tickers that all spawn at the same time) into full effect. They'll be showing up a lot more throughout all the waves of Horde and they've completely infested every 10th wave with nothing but Tickers.

You'll also get double xp over the long weekend, as well as a 500xp bonus every time you're on a winning team. Unless you're playing from an IP address located in England, in which case you'll be forced to wear a bright red coat to make it easier for other players to shoot you.