Scrossler has finally showed his face in the development community of the HTC One M8 with the release of a stock rooted build of the latest OTA. This is simply 1.55.605.2 with no mods or hacks just stock, root, and busybox. This will serve as an easy way to get yourself on the latest and greatest build without having to first return your device to straight stock. Normally you would have to RUU back to stock, or find a way to reenable all of your bloat apps. Then you would need to locate and flash the stock recovery to your device. Then you would be ready to install the official OTA update. Then of course you would need to reflash your custom recovery and then reroot the device. This Rom by "Scrossler" is a much easier alternative. Simply download and flash as you would any other rom in custom recovery. Head to the link below for the download.
Via XDA