HTC Desire 501The Desire 501 comes as an alternative of the HTC One mini. It has a 4.3" WVGA screen, dual-core 1.15GHz processor (almost certainly not a Krait, maybe it's a Cortex-A6 like the Desire 500).
The phone has a 8MP/2.1MP camera combo along with HTC ImageChip, but offers no Zoe support. There's no stereo speakers on the front either.
The 501 also has 1GB of RAM, 8GB of storage with a microSD expansion slot and a 2,100mAh battery. The phone scores in terms of card slot, bigger battery over the One Mini but lacks in 720p LCD screen of the miniThe 501 is not a dual-SIM phone.
HTC Desire 601The HTC Desire 601 has now got a dual-SIM version. The phone is a 4.5" version of the 701, with almost the exact same feature set except in cameras and internal storage front. While the main camera of 601 has a 5MP/1080p shooter, the internal storage has been halved to 4GB.
The 601 has a dual-SIM support, front-facing BoomSound stereo speakers and a dual-core 1.2GHz processor.
There's no indication of which (if any) of these phones will be available worldwide and when.