Limbo is Currently in the Process of Fading from a Favored Theory to an Unfavored Theory
The operative word, of course, is "theory". It was never more than that.
I've never bought limbo myself, but Catholics are free to do so if they like (unless Rome formally condemns the theory). I think it's the fruit of a view of the sacraments which sees them as reducing valves designed to weed out as many people as possible from the mercy of God. I think it wiser to look at the sacraments as the places where we *surely* meet the love and grace of God, but not to pretend that we know these are the *only* places where God's grace can be manifested to us.
Some people ask "Then why evangelize?" This seems to me like asking, "If you've heard a rumor that the girl you've loved all your life wants to marry you, isn't that knowledge enough? Why actually go to the trouble of marrying her?" It's a crazy question if we know anything about love.