Finally I've been admitted into Columbia MBA!!
I applied to Sloan (dinged), Wharton (3rd round, Summer Waitlisted) and INSEAD (withdrawed, since I prefer Columbia). I'm really happy since CBS is my first choice (together with Wharton) and I thought I have few chances (applied the last day of the latest rounds!!)
I have been visiting this great forum for almost one year (not very active, sorry), especially for GMAT preparation (730) and TOEFL (263), but also for admission advice (thanks David!)
My advice for prospective applicants is that you have to put the most in the application proccess (which is certainly time-consuming). Be as active as you can, talk to many alumni, participate in forums like this, go to MBA fairs and believe in your own chances.
In my case, it has been also very important "off-application support", That is, some friends of mine (Columbia alumni) directly e-mailed the Admissions Comittee spending some few good words about me (and believe me, it worked!)
Please, feel free to make any question. Best of luck to all!!. Erin, please, keep doing such a good job!