Yeah the "Loading" text on my game was in Korean.
Most likely broken update, but who knows. Valve recently said that "making trading cards available to all Steam users is a step towards an event we think everyone can be excited about..."
That event is probably the steam summer sale, but hey...
If we're talking about how Valve will announce the game, there's no doubt in my mind that it will be an ARG.
Portal 2 had an ARG, and almost every large TF2 update has had some sort of ARG-like component to it.
They work quite well, and are a great way to get fanbases even more excited about...