Apple has begun sending email invitations to select members of the media inviting them to a “sneak peek of the next generation of iPhone OS software.” The invitation features a large graphic with a large “4” shadow spread across a blue background, with “Get a sneak peek into the future of iPhone OS” overlaid in white text. The event will be held on Apple’s Cupertino, CA campus and will begin at 10:00 a.m. Pacific Time on April 8.