All in-game purchases made with real-world money between October 22 and December 21 will be refunded, and presumably, the game has now turned off future purchases for all players. While the announcement does specifically state that this is an "Open Beta" of the game that's ending, this closure will also eliminate player access to online accounts and profiles, so it doesn't look like any other version of the game will ever launch.
For full details about the closure, check out the official announcement here.
Are you sad to see Family Guy Online closed, or did you never play the game to begin with? Would you have played the game if it was available on Facebook or mobile, rather than just browsers? Let us know in the comments!