Apart from the specific software that comes with the programmer, all 3rd party stuff that I know of actually works via the serial port.
I dont really see this changing myself because from a programming perspective using the comm port allows you to write more generic software. There are obviously phoenix and smartmouse standards. Using the comm port you are able to write the software using these standards, the programmer knows how to understand them; even without the drivers installed on the computer, these 3rd Party comm port apps will probably work.
This is not the case when writing software for the USB port. Using the USB will require either some new standard to be introduced, which I doubt will happen for programmers. Without a new USB programmer standard(which of course is unlikely to work on the old equipement that you would be buying now) the software writers need to cater for every single programmer, which is a huge undertaking, just look how many there are. Sure they might make the effort for the popular ones like inifinity, but its all going to be a lot more work, and you'll start to find that instead of just needing a particular card like the (M2) you'ld end up needing a specific programmer for it as well(I shouldnt give them money making ideas like this).
As for usb having the latest drivers, I think you are better off looking at the make, the more popular ones like infinity are bound to have better driver support in the future, though like I said for as long as they use serial port connections, I'm not sure you actually need the drivers really, since the usb is not being used.
