Merb gets merged into Rails 3
weblog.rubyonrails.org
weblog.rubyonrails.org
That said, I'm a little afraid it will shaft the other Ruby frameworks (Sinatra, Camping). People might make interesting things only compatible with Rails.
When Merb was a pretty big, active minority, it was more compelling to go out of one's way to make interesting libraries (ORMs, gems, etc.) easily compatible with anything ruby.
Rails is gaining modularity, but I fear Ruby overall might lose it. Even after Rails and Merb merge, rails!=ruby.
Anyway, Merb isn't what Merb once was (mongrel+erb.)
This is a special case of Three Systems (from unix philosophy) where the second system was leaner and faster :)
It does seem that Sinatra has been gaining steam lately!
That said, it's all relative. To be sure, people make mistakes, yadda yadda yadda. But I think we can all agree, everyone is entitled to an opinion.