Remember that post I did a couple of days ago about the Microsoft Developer Conference (MDC)? You might want to consider going more seriously now. See http://blogs.technet.com/keithcombs/archive/2008/11/24/did-you-miss-the-pdc-this-year-here-s-another-chance.aspx for the details around the conference.
Looks like Bob Familiar at http://blogs.msdn.com/bobfamiliar/archive/2008/12/02/windows-7-beta-1-for-mdc-attendees.aspx broke the news first. According to him, each attendee will receive a copy. Sounds good to me.
[UPDATE] The MDC website has been updated so you now have another official source of information around this topic. See http://www.msdndevcon.com/pages/about.aspx#giveaways for some additional information on Windows 7 Beta 1 DVD's. It's coming folks.