Rails and Merb are getting merged is old news and everybody is already looking forward for the result, Rails 3.0. This presentation from Yehuda covers how the merge is going. The presentation is around 30 mins and pretty interesting because you get an inside view to the complex merge.

Related posts:

1. Presentation: Rails in the Large by Neil Ford
2. Great Tim Bray interview on the Future of the Web
3. Neal Ford presentation about Software and learn from history