One of the things the community chose that they wanted back in the last community survey was the ability to easily see where users were from with a flag against their comments. We implemented that yesterday, as some very eagle-eyed users have noticed.
There is an option now in your settings that controls whether people can see your country or not. If turned on, the country name appears in your profile, and a flag against the comments; if turned off, the country doesn't appear on either. The default is set to off, so if you'd like to show people the country you're from, then do go into settings and turn it on.
This is a first version of this functionality: our intention is to later add some more features such as the ability to click the country and search for all users from that country, with possibly a finer-grained control of the visibility of the flags. However, with limited time and budgets, we're prioritising the order we do things to the priorities the community has given us. We'd rather get things out there that we've been asked to do, than wait until we think everything is perfect.