"(VeriSign is a company which purchased Network Solutions, another company which was given the task by the US government of running the .COM and .NET top-level domains (TLDs). VeriSign has been exploiting the Internet's DNS infrastructure ever since.)
This will have the immediate effect of making network trouble-shooting much more difficult. Before, a mis-typed domain name in an email address, web browser, or other network configuration item would result in an obvious error message. You might not have known what to do about it, but at least you knew something was wrong. Now, though, you will have to guess. Every time.
Some have pointed out that this will make an important anti-spam check impossible. A common anti-spam measure is to check and make sure the domain name of the sender really exists. (While this is easy to force, every little bit helps.) Since all .COM and .NET domain names now exist, that anti-spam check is useless.