Well this is pretty impressive, both the HTC One and the Samsung Galaxy S4 Google Play editions are getting Android 4.3, at the same time, just one week after it hit the Nexus devices.
As it was said, the update is developed and delivered by HTC and Samsung respectively but they made no modifications to anything, just modified what was needed for Android 4.3 to run on the device. I'm really glad these updates are happening so fast like it was promised, most people was scared that "in a timely fashion" would be just a marketing blitz and the updates would take forever because the manufacturers wouldn't care about the devices. Evidently Google did something right with these deals.
Both updates are slightly different, with the HTC One update weighing 185MB and the update for the Galaxy S4 just 150MB, obviously, both devices need different drives and such, but it's strange to see such a large difference. The only thing where the updates differ is that each phone is getting one new feature each, with the HTC One enabling the IR blaster and the GS4 getting Bluetooth tethering. If I have to guess, it seems that Google told HTC and Samsung that they could add just 1 feature with every update, without modifying anything, just adding something that doesn't interfere with the core Google experience. With the original release, the GS4 kept the lockscreen clock and Smart Cover functionality, while the HTC one kept it's BoomSound drivers and Beats audio.
The HTC One goes for $599 with 32GB of storage and the Samsung Galaxy S4 is $649 for the 16GB version, both available in the Google Play Store. As for the future, both devices look right on track for the next update, there's no reason for these devices to be abandoned now, just like the Nexus 4 I'm sure they all be getting Android 5.0 when it's released. I can't say the same thing for the Galaxy Nexus though, unless the rumors are true and the next iteration of Android is built to run in any hardware.
If you have one of these devices, wait for the rollout to reach you, or start hitting that "Check Now" button every 5 seconds like the rest of us.