Here are more leaks trickling in as launch day fast approaches. I did a little more digging into the CS-321 and I uncovered some accessories that appear to accompany the product at launch. At a quick glance, there appears to be stylus nibs, a nib kit, and a USB charger that will be available for purchase to compliment the CS-321, the latest addition to Wacom's Bamboo line. Looking more closely, one of the product listings for the USB chargers (the very last link below) specifies a May 31st expected availability date, which may very well just be a placeholder release date–or this could be the actual release date!
For your convenience, I noted the manufacturer part numbers for these upcoming accessories by listing them below. It is clear that these are legitimate manufacturer part numbers because Wacom has used the ACK prefix in the past for other accessories and parts, such as for these nibs (click on each listing's individual page to see its individual part number below the button "Add to Cart"). All in all, there are exciting times ahead when there is a plethora of accessories also popping up to compliment this product. This here is further evidence that Wacom is thoroughly investing themselves in this new product sub-category.
Possible release date:
May 31, 2017
Manufacturer part numbers and UPC:
Stylus nibs for CS-321: ACK23016 / 4949268791519
Nib kit for CS-321: ACK42416 / 4949268791328
USB charger for CS-321: ACK43017 / 4949268791533