It has to be that Indian Jones game, I know it!
As if people needed an invitation that something big was brewing between BioWare and LucasArts, media outlets received postcards announcing a special press release set for October 21st. BioWare has a history of making money from a Star Wars game and LucasArts has a history of making money off of Star Wars in general, so speculation is high that there may be a Star Wars component to the announcement. As a matter of fact, I will eat my hat if the game announced is not Knights of the Old Republic Online or some variant thereof. The CEO of EA (parent company of BioWare) confirmed in a round-about sideways glance kind of a way that the game exists back in July. Ergo, this announcement should fall into the category of anti-climactic (unless they provide a release date which would send heads spinning).
So look for some exciting news in a few weeks about the new KotOR Online or about some other game they cooked up. If it's KotOR we'll all be excited, and if it's something entirely new we'll all be excited and I'll be in the corner eating my hat. Gamasutra has a little more about the announcement.