Simply put, VID is 16 bit wide, so is there any potential issue of exhaustion (like what is happening with IPv4 ?
How far we are from this moment, where can we get the actual number of allocated VIDs ?
Yes, there is a potential issue of vendor ID exhaustion. As the maker and startup communities continue to grow, more people will want to make USB devices on a small scale.
USB vendor IDs are controlled by the USB Implementers Forum, and they currently charge $5,000 per vendor ID.
The USB-IF does not release any reports about how many vendor IDs are taken as far as I know, so we can only speculate. There is an incomplete, unofficial list of vendor IDs and a list of vendor IDs from Microsoft.
In my opinion, they should have made the vendor ID be 128 bits wide, just like the GUIDs used in many places in Microsoft Windows.
If we start to run out of vendor IDs, the USB-IF will probably issue an Engineering Change Notice allowing some way to increase the vendor ID space. For example, they might expand the size of the USB Device Descriptor or they might make a VID with a special meaning; when the host sees this special vendor ID it could run a special request to get the full vendor ID which would have more than 16 bits.