Congratulations is due to all who got the call from Chicago GSB. I remember the feeling, a sweet mix of surreal and joy. For others who couldn't make it, I am sorry for ya because I remember that feeling as well, it wasnt nice at all. Just remember that this is not the end of road.
The third segment of the population, people on the WL. What can I say - you probably dont know if you should be happy or sad, right? Take my word, dont be sad because you still have an opportunity in hand. Yes, it might need some more work, but you still got a chance. Dont give up just yet. Let me share some quick thoughts on what I would do if I were on the WL
1) Read the instructions given by the school. Do as they say. You might here one off stories where people disobeyed the instructions, did what they wanted to do, and still got an admit. Do not take that as a rule, because in high probability you would not be able to imitate that one off case. Be safe, follow the instructions.
2) Be creative. Within the realms of what you are allowed to do - try and be creative. See if you can grab attention by bringing in a new way of approaching the same problem. For example, if the school accepts additional material, do you want to send once every fortnight or just once in three months ?
3) Keep in touch. With members of the adcom. But realise that they are going to be really busy people over the next few months (till R2 decisions) - so appreciate the value of their time. If you had the opportunity to connect to them before this decision, leverage that. If you can visit the school and make some new connection, you can do that too. My hunch says that just sending an email or calling wont quite cut it at this juncture if you havent done something before - so focus your energy elsewhere. Another way to gain visibility is to use the schools admission forums - just make sure your handle(or nick) can tie back to your name, and dont ask straight forward questions, please!
4) The trick about extra essays. Make sure there's as much substance in there as was in your essays, maybe even more. Are there any recent developments (career or outside accomplishments) you want to let the adcom know about. Dont send shallow essays just to show interest, it wont add value and can make the adcom question your judgment. Very important - your new essay shouldnt repeat anything you have mentioned in the essay or the application already. Make sure it adds on to what you have, otherwise your judgment might be questioned again.
5) Make essays personal. And I think this applies to the normal essays as well, not just the WL ones. Did you talk to any alums, any current students, or any staff members? Did they or the opportunities in the school strike a chord in you like never before. If yes, mention that (remember : dont repeat stuff though). The usual essay advice of being terse, showing school love, etc all still applies.
6) The trick with recommendations. If the school allows recommendations, use that opportunity. Send some meaningful recos, some heavyweight recos if you can. Pick a recommender who can highlight some new qualities, something you might have ignored(or not have the space) to show before. The trick is to bring in a new shade of yourself.
7) For GSB, you will have from now till some date in March when you can send additional material. Make sure you space out your material (= essays + recommendations) over these three months so that you are regular touch.
8) That's all for the ideas, but before you do all that, take some time off, just relax. Come back and take a few days to read your applications, ask friends in the respective school to read it as well to find what might not have worked. Then start from point 1 above and plan out a roadmap.
If you have questions on the above, feel free to email me or just leave a comment and I can share my thoughts.