This sounds like a cool event for web developers, here is the marketing blurb:

Attend the MIX conference, a LIVE! conversation between web developers, designers and business leaders, being held in Las Vegas from March 20 - 22 at the Venetian hotel with Bill Gates and Tim O’Reilly.

Click here for more information or to register.

Note that is Bill Gates and Tim O’Reilly,  the publishing and open standards guy.  Not to be confused with the Fox News guy Bill O’Reilly