From Ask A Jedi:
G4 TV officially starts their live E3 broadcast coverage at 3pm Pacific time tomorrow, Monday June 15th.
Interestingly, this just so happens to coincide with the end of the countdown timer on the home page of the official Star Wars: The Old Republic site.
While we already know that G4 won’t be doing their promised 30-minute coverage of The Old Republic until Tuesday, this does make it likely that the new cinematic trailer will be revealed between the hours of 3:30pm and 6:00pm, which is after the EA press conference.
Hit the source for the full article.
Source: Ask A Jedi