Paragon Chat is not the City of Heroes revival that everyone wants, obviously, but it is a chance to walk around, chat, and enjoy the environment and the costumes within the game client. A recent tweet from the people at Titan Network responsible for the chat service reveals that the sort-of-game has seen 788 accounts connect to the service, with a peak concurrency around 200 people.
If you want to step back into Paragon City in some capacity, a detailed guide is available on the Paragon Wiki, which also provides a comprehensive overview of what is and is not available within the chat service. You can also jump down below to see the chat client in action in a video from Somewhat Eclectic.