As we followed the community's request, we've contacted Bittrex a few days ago.
A few hours ago we got a response from them :
Thanks for the request. Our policy is to not comment on whether we will launch coins but we only add coins under active development with high community demand.
We gauge demand based off of tweets, hash power, length of bitcointalk thread, volume on other exchanges, etc. Follow us on twitter @bittrexexchange and tweet about how much you like this coin and Bittrex. We respond to creative and insightful posts to help market your favorite coins and Bittrex. I'd also consider coming to our irc channel #bittrex on irc.freenode.net and do some guerrilla marketing. The traders there can help you gain exposure for your coin.
So, following their "requirements" we would like to ask you, our community, to express your interest in being added to Bittrex.
Regarding the first consensus poll, we are getting many responses from you by the form, and the most "requested" developements are starting to clear out. Keep up the voting, remember you can submit your proposals until 23th of March