Microsoft has confirmed one of the worst-kept secrets in tech: The next Xbox will be revealed on May 21.

The company on Wednesday morning sent out invitations to the media for a product unveiling.

"A New Generation Revealed," the invitation reads. "Don Mattrick and the Xbox team invite you to the Xbox campus for a special unveiling." (Mattrick is the president of Microsoft's Interactive Entertainment Business division that includes the Xbox.)

The company plans to broadcast the unveiling live on the Xbox, as well as on Spike TV.

Earlier this month, longtime Microsoft blogger Paul Thurrott broke the news of the date of the debut in an interview with the video blog "What the Tech." (His comments about the next Xbox start at the 54:44 mark.)

The Xbox 360 has been the king of consoles in the United States for more than two years, outselling the Nintendo Wii and the Sony PlayStation 3. So Microsoft has been in no rush to debut a new version, preferring instead to let rivals show their hands.

That's why the unveiling of the next Xbox will be the last among the big three companies. In a bid to get ahead of the competition and jump-start its sagging console fortunes, last November Nintendo launched its Wii U, which comes with a tablet-like game controller that doubles as a second screen. In February, Sony took the wraps off the PlayStation 4, which has a far zippier graphics engine and beefier storage than its 7-year-old predecessor.

Microsoft's gathering will come three weeks before the giant E3 gaming trade show in Los Angeles. The company is likely to unveil the technical specifics, as well as talk about the entertainment focus of the Xbox that goes beyond gaming, at its May 21 event. If history is a good gauge, the company will show off some of the biggest gaming titles for the next Xbox at E3.

Update at 10:50 a.m. PT: More details and analysis added.