For those who don't know (and if you aren't Twitter users, why should you? And if you are Twitter users but don't care, why should you?), Twitter changed their way of handling @ replies a day or so ago and all Hell broke loose in the Twitterverse.
[What follows may seem gibberish to those who don't use Twitter]
RT @parislemon Twitter: The Dog Ate Our Homework http://tcrn.ch/1xr [Biz explains @ replies change]
Someone who reads my Twitterfeed read the post above and wrote
I still don't get it. ...
Imagine you can turn on/off whether you'll see the @replies of someone you =do= follow to someone whose Twitterfeed you =don't= follow.
If your switch is OFF and I @reply to my brother, you'd never know. However, some people (3% of the Twitterverse we're told) like to see @replies even if they don't know the person the @reply is directed to because ... well, because they get curious and go check that person's Twitterfeed and find new interesting people. (Sometimes....)
Twitter designed their software so that each time someone made an @reply, Twitter was spinning through their followers list to see which followers wanted to see @replies for people they didn't already follow, so they could show them the @reply.
That's fine for thee and me, but imagine what happened when Ashton Kutcher made an @reply. Twitter was spinning through each of his million + followers to see who wanted to see the @reply.
Ooopsie! Fail whale!...
Bad design. Badbadbadbad.
so, is it fixed?
Not fixed. Will never be fixed. Can't be fixed, actually, because the underlying design is flawed.
If their design is such that they have to loop through a linked list of all the folks who follow TwittererA to decide who does and who doesn't get notified of an @reply, they have something that just can't be scaled to an Ashton Kutcher level.
Right now it sounds like Twitter is trying to come up with something else that will give some of the functionality the upset cohort is upset about losing.
They've already implemented a simple partial fix. If a person is posting an @reply but not using the [reply] button to do so (i.e. they're typing @username rather than clicking the [reply] button) the @post will go to all the Twitterer's followers. Maybe that will be serendipitous enough.
Sounds like whoever designed the @reply part of the code never imagined there'd be multiple users with over a million followers. "In your dreams, guys." Well, some times dreams come true.