Valve isn't mentally ready to share the sheer awesomeness that is Half Life 2: Episode 3. Ok, perhaps not mentally ready, just not ready in general, according to Valve writer Chet Faliszek.
In a call with News.com.au about Portal 2, the burning question inevitably slipped in with Faliszek replying, "We're not prepared to talk about that at the moment," before jokingly pretending to get cut off from the call due to bad static interference.
On that note, apparently G-MAN is Gordon Freeman from the future and the great-grandfather of Alyx.
It's a joke. We hope.