It is hard to make suggestions when you don't know what to expect or what changes have been made over last year. A track listing would help with this.
Posting tentative schedules would help and it could be with full understanding that the schedules were tentative.
Hotels in downtown Seattle are very expensive, so wondering if there might be some option to help groups of delegates stay a as a group further from the CBD and share transport in/out of the venue each day.
Especially for people visiting from overseas. Could be a great chance to share tips/tricks.