I seem to remember that something, which wasn't tickets but included details of the seminars, arrived shortly before the exhibition. If you've already registered, you've probably received the seminar schedule by now. Thursday's is on the site at present, but no sign of Friday yet
http://www.windex.co.uk/content/blogcategory/20/28Don't take this schedule as gospel though, the seminars WILL change!
If you pre-register they know you'll be going and there's a name badge waiting for you when you arrive - saves a bit of faffing about. The amount of junkmail/emails you continue to get after the event depends on what boxes you tick
If you want to take employees/spouses/boyfriends along it's best to register them as well, but say they don't want contacted in the follow-ups.