Valve appears to be rolling out the red carpet for something big in Team Fortress 2. A countdown clock ticking towards today at 5 PM PT has appeared on the official site.
It's hard to draw any conclusions about what might be coming to the long-running shooter, but Valve has made large changes several times throughout its seven-year run. It went free-to-play in 2011, helped kick off Steam trading, and introduced a Mann vs Machine mode. Valve has even stated that it uses TF2 as a test-bed for new concepts that it then adopts company-wide.
You can watch the countdown clock tick towards zero here. Put your best guess at new modes or fancy hats in Chatty while we all wait to see what it is.