Police claim to have the individual allegedly responsible for the entry in custody, as well as the computer that the entry was said to have been made on, but they won't make his/her identity known to the public until later this week.
As always, until an official announcement is made, take all rumors with a grain of salt.
How did the police track the alleged poster, especially so quickly? Here's a tidbit:
"What the anonymous user on Wikipedia may have failed to realize, is that little about your activity on Wikipedia (or the rest of the internet) is anonymous.
Anytime an edit is made to a Wikipedia page, that information along with the user's IP address is logged by the site and publicly accessible. A simple check of these logs paints a much clearer picture of the person who made the aforementioned edits: not someone affiliated with the WWE as the mainstream media suggested, but rather a teenager from the University of Connecticut who just finished his first year of college and vandalizes Wikipedia on a regular basis."