Microsoft has canceled the sessions to "optimize for the four main days of the event". For those who are attending the conference, this unexpected last minute change will cause unnecessary travel expenses as the press will now arrive early to the event.
Here's a cached version of the Build page showing the scheduled pre-conference:
The pre-conference sessions had not been unveiled, so what Microsoft was planning to show off at that time is still unknown. At this point, there is only speculation on why Microsoft pulled the plug on the event.
Microsoft states about the cancelation:
"In order to better focus on all the new content that will be covered at BUILD, we decided to optimize for the four main days of the event, which will include an enormous number of speakers and sessions. Registration is open on Monday but there will not be any formal sessions for attendees that day. We're communicating the change now so people have the option to change their travel arrangements.
Microsoft has positioned the Build show as a replacement for its Professional Developers Conference (PDC) and WinHEC (Windows Hardware Engineering Conference) -- at least for this year. There's no word as to whether Build will be a recurring event or how much (if any) Windows Phone, Xbox/XNA and/or Azure development content will be included as part of the conference.
Build is expected to focus on Windows 8 and the Windows 8 development platform.
[Via: All About Microsoft]