HTC One X and S handset will be the first devices to receive Android 4.1 update.  Unfortunately, it’s not the  case for all HTC devices.   HTC confirmed that devices with 512MB RAM or less  will not receive Jelly Bean updates. The list only includes HTC One V and HTC  Desire C.  and HTC notes that the devices will still get ongoing support, just not the latest Android operating system. HTC says the decision is an attempt to “ensure each of our products has the optimal user experience.” As for other devices, HTC is working to bring 4.1 updates to its current lineup of phones before addressing older models.

Source: The verge