By Aidan Malley

Published: 08:35 PM EST

The Wall Street Journal's increasingly influential technology conference is about to begin, and may bring multiple announcements from industry giants -- though Apple isn't talking.

The annual D: All Things Digital conference has become more and more pivotal for the technology industry since its inaugural event in 2003. Typically centering around a series of interviews by columnists Walt Mossberg and Kara Swisher, the event has typically served as a platform for more outspoken company heads that want to outline their grander visions or reveal previously unknown facets of their company culture.

Perhaps the most important of these to date, however, is set to take place Wednesday night. Apple CEO Steve Jobs and Microsoft chair Bill Gates will both be subjects of a joint interview by the journalists. It will represent the first time the two will take the stage together for an extended period and should free both executives to talk openly about themselves and each other: as in earlier years, the 2007 D conference will avoid scripts and other conversation filters.

Either firm will also have its own time to speak candidly about its own future in separate events. Jobs will appear onstage separately in advance of the interview to discuss Apple's strategies, while Microsoft CEO Steve Ballmer will take a similar approach for his company.

More immediately relevant to those not present at the sold-out gathering, however, will be a likely flurry of product announcements that have been a staple of more recent conferences.

One of these is now known to be coming from Microsoft itself, courtesy of a company mistake. The Redmond-based firm on Tuesday unwittingly sent news site Gizmodo e-mail confirming that Microsoft's Entertainment and Devices division intends to release "something totally new" at the conference. While details are vague at best, the company is said to be sparing little fanfare and is promising nothing less than changing "the way people interact with technology" -- a significant claim by the same Microsoft branch responsible for both the Xbox 360 game system and Zune media player.

If Microsoft has been only reluctantly vocal about its plans, however, Apple has said even less. The Mac maker has said nothing of its plan of attack for the conference and has publicly revealed nothing of what products, if any, will be released to accompany its CEO's stage appearances.

Even so, Jobs has already established a brief but identifiable track record of matching his appearances with announcements. The CEO in 2004 revealed Airport Express, and just a year later showcased podcast support in a look at iTunes 4.9 weeks ahead of its official debut.

Whatever may stem from Apple, the company will invariably become a subject of comparisons thanks to one of the few officially validated announcements. Palm intends to preempt Apple and Microsoft alike by unveiling a "new category of mobile device" through a press conference to be held Wednesday morning. Company founder Jeff Hawkins is heavily favored to launch a handheld so far known only as the "Hawk" -- which has been rumored to be anything from a direct challenger to the iPhone to a cross between ultra-mobile PCs, smartphones, and other communication-savvy gadgets.