Yesterday, if you had typed www.somerandomname.net, you would have gotten an error message from your browser. Today, you get a Verisign-sponsored web page.
Today, the web page contains a search box and a list of "Popular Search Categories", which take you to Verisign's sponsored search pages.
In a really odd quirk, sometimes it provides useful "Did you mean?" entries, which are relatively close matches (such as replacing the .net with .com or .org if those domains exist).
Either way, once again, we've been sold out by ICANN, because Verisign not only gets your clicks, but gets to know what the most popular misspellings and most commonly tried web sites are (something that previously wasn't the purview of any internet provider, although Microsoft has a "feature" in the Windows version of Internet Explorer that captured this same data in a similar way).
Technical implementation specifics can be found at Verisign's site.
I'll also note that you can no longer "ping" a random domain name to determine if it exists. This is because Verisign's wildcard will now give you a valid IP address for any .net or .com name, although the server at that address will not respond to pings.