A VG247 source has claimed that Valve's "surprise" at E3 will be the unveiling of Source Engine 2.
The source, who wished to remain anonymous, said it's possible Valve will be showing Half-Life 3 running on it - which would fit with the firm's M.O. of showing Half-Life games on new versions of the code.
Half-Life was shown running on GoldSource, while Source debuted in June 2004 with Counter-Strike and Half-Life 2 shown on it.
Rumors surrounding Valve's plans for E3 have been swirling about since it canceled its Portal 2 event for the conference, stating that a "surprise" would instead be in store for attendees.
Last week, a suspicious looking image taken of the E3 pamphlet that supposedly showed a date of June 14 with the name "Freeman" on it when converted to negative format surfaced.
While very dodgy looking, it still got folks to talking, enough to have Valve head Gabe Newell confirm that it was indeed a "fake".
We have been told by Valve PR that Gabe himself will not be attending E3, so take all this with a giant pinch of salt.
It's worth noting, however, that we've also been told that whatever Valve plans to reveal at E3 will not happen before either the Microsoft or Sony press conferences on June 14 and 15, respectively. So it's quite possible that whatever surprise it has in store could happen at one or both of those pressers.
Rest assured, we will be liveblogging both events, so be sure and check in with us so you won't miss anything.
In the meantime, we've mailed Valve for comment, so if we hear anything back we'll update this post accordingly.