> Realistically, what would they do if you showed up in jeans?

Nothing at that talk, but you may not be on the invite list for next time. Microsoft's invite list for TechEd is notoriously political. The leader for each track (an MS employee) picks the session list.

To give an extreme example, one of my submissions was called something like "Fixing Slow SQL Servers." I was told, "At TechEd, there are no slow SQL Servers." It was changed to Building the Fastest SQL Servers. (sigh)