Hey all, I'm a Kellogg 1st year and former waitlister. For those of you still awaiting decisions--I know what you're going through. I was a 1st round applicant last year and got accepted (finally) on 5/7. A shocking number of the most talented folks I know at Kellogg were WL'ers, and one was accepted very late in the summer. I didn't really do much of anything to promote myself off of the list last year, but YMMV.
I was really frustrated this time last year, but have ended up extremely pleased with the final outcome. At the end of the day, nobody cares how/when you get admitted.
If anyone has any questions or wants to chat after getting a final outcome, feel free to PM me.