According to this GameSpot article, Sony will be kicking off E3 with a pre-conference gathering in which we will hopefully see them disclose all those juicy tidbits of information regarding the PlayStation 3's launch details. Two days before the expo begins (May 8th) is when everyone will get the skinny at the Sony Pictures Entertainment Studios in Culver City, California.
"Pre-E3 gathering to reveal launch information?" - 05.04.06