> So Windows Phone is updated at the will of the carriers as well?

You can register for the Preview for Developers program [1] and get timely OS updates regardless of the carrier.

With the 8x the lack of updates is an HTC issue tho as far as I know. They look to roll out 8.1 on some of the 8Xs in October [2].

[1]: http://www.wpcentral.com/preview-for-developers

[2]: https://twitter.com/htc/status/509409362100879361