The Google Play Edition of the HTC One M8 was announced yesterday with the international version of the device. And today the GPE variant is already in Stock.
The Google Play Edition though costs about $50 more than the original version and also the Developer Edition of the HTC One M8. The GPE version is unlocked and would support the AT&T and T-Mobile networks in the United States. At the moment the GPE version is only available in US, but when it is made available outside US most probably it would work with most of the GSM carriers.
Also apart from the fact that it runs on the Stock Android, still the duo camera works. You can order the Google Play Edition of HTC One M8 from the source link below for a price of $700 and it would ship within one or two business days. Checkout the all new features of the HTC One M8 described here.