Symantec is a well known company that tried to push hard in the enterprise sector, so verisign customers will at least have heard of who is taking over. My thought is that it will be like Comodo, since Comodo is an authenticator and has a security suite, and now Symantec will be an authenticator with a security suite. The only difference is that Symantec will cost more than Comodo.
I doubt that now that Symantec has digital certificates to sell, they won't give Norton away for free. Verisign was a trusted authenticator and I too applaud them for lasting as long as they did. They tried making the web a safer place. Let's hope that they still have as good a quality and trust being under Symantec. I think they will, but only time will see what happens.