XDA developer, Saumitra Yadav has ported the TWRP recovery to the Motorola Moto E. This officially makes the Moto E, one of the cheapest smartphone and customizable at $129. As the Moto E currently runs on KitKat 4.4.2 and has a MicroSD slot, this makes this device ideal for anyone who wants a low cost smartphone with expandable storage.
The immediate benefits to rooting would be further optimization to Kitkat on Moto E thereby improving battery life and overall performance. This also opens up to the doors to custom ROMs which enables users to choose ROMs based on the features they want. In addition, it would allow for the removal of bloatware which are usually installed as system apps.
The second beneficiary is the enabling of third party apps to write to external storage. This is pretty useful in avoiding situations in which the Moto E is bricked or damaged in some way. It allows the use of apps such as Titanium backup to backup app and app data or file explorers such as X-Plore to make modifications to the files on internal and external storage. In addition, NAND backups can be done to enable a full image backup of system and user apps & data.
The third advantage to this, is the modification to KitKat as a whole. This could range from themes or the ability to save photos onto the external card without having to flash a ROM. In this case, Xposed Framework is what is needed as it allows for modules to implement such system-wide changes.
As of now, as both the TWRP recovery and Moto E are relatively new, these 'features' might not yet be fully functional or readily available. Touch support for the TWRP recovery only works after the Moto E has gone to sleep and woke up. ROM-wise, there are none which again should be attributed to the newness of the device. For anyone with a low budget and wants a hackable device, the Moto E might just be such a device.