It better be EP3 and not just Portal 2.
The slightly More Orange Box™
Portal 2
Half-Life 2 EP3
Team Fortress Orange X
Actually according to a SPUF admin, Valve is moving their offices so it wont be anything big. Yet.
You know, for as much as people whine about debatably bad TF2 updates and what-not, no other major game company in the world would ever take as much time as Valve most likely has to release a crazy update like this.
Valve did say that they had no plans to release any other kind of orange box afterwards for say episode 3 or portal 2.
So the chances are you're all barking massively up the wrong tree and that portal 2 is about to be announced completely stand alone, which is we'd have expected. (or at least anyone that can remember interviews from way back would expect)