Sorry if I am coming over as offensive, but I just need to share that it feels kind of weird when you submit a business idea like that, get rejected and than 5 months later read about how yc chose somebody else (who had already in the program before) to create a business - which is just your idea - and he had it like 3 to 4 months ago. Of course the idea for such a thing will always be born in many heads at the same…
Without knocking YC: if you really feel that this is a great idea, and you really feel that it is doable, then just go ahead and do it. (Sure, you now have 1 YC funded competitor. Eh, who cares. Competitors are God's way of telling you there is a market which will pay to be satisfied. If you don't see any you should be scared. You can both still be successful.)
However, the potential competition is probably a good thing.