(updated: July 29th 2015, added Windows 10 final ISO location)

A new feature has been integrated into the Target and Apply pages, the ESD conversion.
ESD stands for Electronic Software Download, it is what Microsoft uses lately to compress their online distribution of Windows 8 and 10 ISOs.
Only Windows 8 and newer support ESD image format installation, so the following options are disabled if you select a Windows 7 image.

The way you can use ESD conversion in NTLite is pretty straightforward.
Unpack downloaded ISO content into a folder and add that location to the target list via the Add button on the Target page toolbar.
ESD images are automatically recognized, you can try to Load them at which point you will be offered to first convert the image to the standard WIM (Windows Image Format). That conversion is necessary for mounting and editing an image.
Conversion can be triggered manually by selecting an image container (namely Operating Systems), and choosing Convert from the page toolbar or context menu. Convert option toggles the image format to WIM or ESD accordingly.
You can also directly export a selected image to any of the two image formats, using the context menu Export option.
With Export you can isolate the main image and choose a destination, while Convert takes care of preserving the original ISO structure.
Proper folder structure is necessary for installation to work even if you are copying the folder content to an USB drive.
In other words don’t use Export unless you know exactly what to do with the exported image.

What about the other way around, the WIM to ESD conversion.
ESD images are smaller, so that means we want it. For that reason there is an option to compress WIM images to ESD.
You can compress to ESD from multiple locations as well.
Either the same Convert or Export options, or you can use the convenient Apply page toolbar automation section and check ESD Compression option.
That will automatically compress to ESD after WIM editing has been completed, after which you can also queue up ISO creation using the same toolbar.

If you wonder where to get ISOs legally:

• Get Windows 8.1 ISO
• Get Windows 10 ISO
• Get Windows 7 SP1 ISO (requires a retail product key)

Note that only decrypted ESD format is supported, meaning only that you allow Media Creation Tool to do its work and prepare the ISO, then you can convert it with NTLite to the editable standard WIM format.

Feedback is appreciated, enjoy.

p.s. a forum member cActusjUiCe has posted a short, but informative, guide about using Post-Setup page in NTLite, check it out here.