It has been made clear from numerous sources that Twitter does not plan to ditch Rails (at least not entirely), and there has been no public statement to the contrary since this prediction closed. The community was correct. --The Industry Standard

So, the Twitter/Rails scalability debate is heating up again, but this time it might be for real. And a recent e-mail from Biz Stone to Twitter users announces some newly hired non-Railsies:

"We’re thrilled to announce two talented new team members. John Kalucki is an experienced distributed systems architect well versed in relational messaging as the former co-founder of San Francisco based SQLstream. Steve Jenson is a familiar face for a few of us here at Twitter HQ because he’s a former Google software engineer known for his work scaling Blogger and Blogspot–a service which tens of millions of people use on a regular basis."

Which seems at least an implcit acknowledgement that big changes are ahead, regardless of whether those changes involve a migration from Rails. Interestingly, eWeek today posted a positive story in reaction about Twitter and Rails scalability best practices.

This is a prediction that Twitter will decide to move away from Ruby and Rails (both the scripting language and the framework). What they ultimately migrate to is outside of the scope of this prediction. The migration need not have actually taken place -- the intention only need be made explicit. If Twitter decides only to move "part" of their infrastructure away from Rails, but still leaves some of it intact (Evan Williams has publicly suggested that already not all of Twitter is built on Rails) this prediction will still be judged favorably, provided that the part migrated away from Rails is significant -- and how "significant" is interpreted will ultimately be left at the discretion of The Standard's editors.

UPDATE: Ev is not taking the bait, echoing statements he's made before about Twitter using a mix of Rails and other languages, and insisting that Twitter is going to stick with the popular framework. But we're not going to take his word for it -- his tweet might be all smoke and mirrors -- we're going to keep the prediction open for a little bit longer -- seems like community agrees, too, that Ev might be pulling our chain with the denial.