Hatstand
Maybe I am just too old school, but to me a sampler (in hardware terms) could record  a sample, edit a sanple and playback a sample. While a number of plug ins mentioned above will do the edit and playback, it will 90% of the time require a stand alone to record a sample whether it is live or as part of a stream of non copyrighted material.
There are a lot of these about, I have just bought Iris 2 which will do two out of three, but also have numerous others including simpler which also does the same two out of three.
 
Not exactly helpful I know, but it helps define the scope of what is required.
 
 

True for the most part except a DAW can record samples. A sampler as you and I understand them is not needed anymore so long as the player can edit them and play them back. I'm not sure the editing is required either.  Really things have changed so much that terms that use to have one meaning may no longer have that same meaning. I think we need to clearly define what we mean by sampler. 
 
 
 
 

John
I think we need to clearly define what we mean by sampler. 

For my own use case, I would be perfectly happy with something along the lines of Ableton's Simpler or Studio One's SampleOne, as the OP suggested. Of course, if the bakers want to drop an integrated TX16WX on us, I welcome the opportunity to have at it.
 
I don't need any sample content/libraries, as I have plenty of loop/sample packs and I can create my own.

Forgot to mention this earlier but one of the samplers I use to build SFZ librarys is called Sforzando.
https://www.plogue.com/products/sforzando/
 
not sure it would be up to standards for some of you hardcore sampler users but it has its uses.
pretty stable as well.

vdd

abacab
Before you can create something, you would need to hammer out the functional requirements and design specifications.

OK, let me try:
- Ability to record samples within the plug-in
- Ability to slice, loop, cut ... (edit) the sample
- Support to create keymaps
- Stretching & transposing of samples
- synth functionality (excluding the OSC)
 
= basicly one of the great synth like Rapture with an additional window to do the first four points...

That's a pretty good summary.

How about amalgamating dropzone into Rapture Pro, and trickling this down to rapture session. That way dropzone gets updated, and Ratpure moves up another level, Sonar gets an updated sampler.
 
I assume the guys that work on Rapture aren't the same that work on Sonar, so no resources are taken from Sonar, but it benefits too. 

a sampler is prime candidate for a paid add-on imo

pwalpwal
a sampler is prime candidate for a paid add-on imo

It's not from Cakewalk, but consider Reason Essentials - $69 and rewires into SONAR. It includes the NN-XT sampler (which is a very capable sampler), Live Sampling editor, ReDrum drum computer, Dr. Octorex, Subtractor synthesizer, and can create REX files. Seems like a good deal for the price.

Reason Essentials looks interesting for live sampling.  The NN-XT Sampler and Redrum drum computer are demonstrated in this short tutorial.
 
Reason Micro Tutorial - Live Sampling 101
https://www.youtube.com/watch?v=JZp4ihGyrpM

After reading this thread, I checked and found I do have DropZone (x32) installed.  I instantiated it and played with a few presets.  Looks to be a cool little sampler.  I'm not sure how much work it would take, but if this was ported to x64 it might be a good one to add to Plat.

BobF
After reading this thread, I checked and found I do have DropZone (x32) installed.  I instantiated it and played with a few presets.  Looks to be a cool little sampler.  I'm not sure how much work it would take, but if this was ported to x64 it might be a good one to add to Plat.

Maybe, but it seems to be missing a lot of "sampler" features.  It cannot record or do wave editing.  It's a basic sample playback synth.
 
I'm guessing that Dropzone would need a good bit of code added to even begin to look like TX16Wx, so if you are going to drag and drop your waves into a sampler, might as well use that.