What I would like to see more at TechEd events are the instructor led hands-on sessions/workshops. There were a few of those the day before the actual conference started in Orlando last year about SQL etc. And those were interesting.
The pre-conference full-day seminars are interesting but would even be much better if they were hands-on (even with your own laptop). All day only listening to a presentation is tiring. That's also what I heard from other attendees every year. Are you guys considering that? Or is there a reason why you don't want to do it?