It all started with this:

Subject: A note from Aperture Science

Dear Subject Name Here,

Aperture Science is pleased to inform you that we have partnered with Valve to announce the gala CANCELLATION of the June 14 Portal 2 event at the Regal Theater. The event will be replaced by a surprise. And even though the cancellation of the event certainly counts as a surprise, we are pleased to further announce that the cancellation of the event is not THE surprise. However, per International treaties regarding the definition of the word "surprise", of which both Aperture Science and Valve are signatories, the time, date and content of the actual surprise will only become available as you experience the surprise.

If you'd like to ask fruitless questions about the E3 Portal 2 surprise or, more fruitfully, schedule an appointment to attend a Portal 2 screening at the Valve booth during E3, please contact Valve's Special Envoy to Surprises, Doug Lombardi.

Thank you for <<RECORD SCRATCH!!!>>

PS: The surprising record scratch is also not the surprise.
So what could it be? CSS2, HL3...or a completely new IP? Obviously everyone's hoping for EP3.

But what proof do we have of it being EP3? Just check out this pic from the TF2 blog:



But wait, what's this?



And there's more! You can see a faint outline of Gordon's face.



Either way, I guess we'll find out on June 14th .