The “in reply to” links are currently missing on twitter.com. However, we found them, and they will re-appear today.
We’re working on a few problems related to the ongoing rollout. These should be resolved quickly and it will be back on for those who had the Retweet feature previously. And we’ll then continue the incremental rollout of this feature to everyone.
We’ve been contending with an elevated number of errors since late last night. We’ve ruled out a number of causes of this problem but are still working to reduce the number of errors on the site.
Update (12:35p): We’re continuing to make changes and are seeing errors return to more acceptable levels.