Guys, I don't want to be a Negative Nancy, but I am almost sure HTC won't do jack to make it work. They are pretty low as a company overall at the moment, and the 8X is the last phone they've released which has Windows Phone, and it has absolutely no support. HTC is known to have crappy support, but this is just ridiculous.
I am planning to let them know how I feel about their product too... Deeply disappointed, I would really have loved to have Cortana. Really hoping someone comes with a workaround.