It's summer, so it's time for the don't tell anybody that you are on vacation because bad guys are reading your Facebook page and will rob you articles.
I'll admit, it seems obvious. However, a quick Google search failed to produce a single confirmed case of an empty house being robbed specifically because the criminal knew the owners weren't home via social media. There are a couple of cases of a tweet or Facebook update that are correlated with homes being robbed later, but any reader of this blog should know that correlation is not causation.
Unless you are an idiot, your Facebook updates are restricted to friends. Presumably, you are not in danger of being robbed by your friends. And if you are, the problem is not your self-editing of FB updates, it's your choice of friends. Twitter, generally being public, may be a bit more of a concern. However, your "I'm in Miami and have the morning free, anybody want to meet up?" tweet is one of hundreds of millions streaming on Twitter that day. For that to cause you to get robbed, the criminal must be following you on Twitter, know your address, be in your hometown, and be comfortable that you don't have a house sitter, large dogs, security system, etc. I'm not saying it can't happen, but it doesn't seem likely.
So the risk is small. Are there any rewards to announcing your vacation or travel plans? People meet up all the time because of this sort of thing. You might make important business connection because you have the morning free and somebody you have some connection to does also. You might meet up with a friend of a friend and get a tour guide for the day, or a backstage tour of a museum because a friend of a friend is the curator of the museum. You might get insider restaurant and club recommendations, a line on a good babysitter, or any number of interesting benefits by connecting with somebody local with whom you share something.
The risk versus reward analysis favors the potential rewards, IMHO. You can decide differently, just don't do it based on paranoia or hyped up media reports.