blanketbird just keep calm and smile a lot, be yourself and meet as many people as possible! Good luck!
primaveracero good luck!! i have been reading all your post along this forum, and i know you are well informed about everything, now it's your time to show them how you are, but try not to show that this job is what you most want in the world, make them see that they need you in the company !!
Good luck!! And do not forget that it's an assessment, and they are looking everything, how you smile, how you speak, even how you walk (that's so important!!). Also try to avoid silly questions, and keep eye contact with your collegues, try to avoid looking to the recruiters, if you are chosen to explain something to your group, explain it to your group!... you know what i mean??
Good luck, and remember that they are recruiting so many people and the waiting time it's not that long, my GC just last 2 weeks since my FI!