Fistly, it could be a bit tedious to the receiver players (if there are a lot of them connected).
On the second, the term connected is deceiptful, because the http connection is instantaneous. I put the name in the bottom as connected when the last http request was 200 seconds or less. May be this people close their browser and go out 100 seconds ago and you can see it below yet.
But, due to the existence of the chance of send a message to all own games (i dont like it), i suposse that a messsage to all connected isn't too worse...
Achiles(X)