Trailing slashes in URLs causing routing errors in 2.3.0 RC1

I just noticed that after updating an app to 2.3.0 RC1 (from 2.2.2)
Rails now raises routing errors when it sees a trailing slash on the
end of URLs for resources defined using the ":as" option.

eg. given a resource like this:

     map.resources :articles, :as => :wiki

Accessing "/wiki" works, but trying "/wiki/" does not. (Both used to
work in 2.2.2.)

With a resource that doesn't use an ":as" setting:

    map.resources :posts

Both "/posts" and "/posts/" work as they did before.

Anybody else seen this? Could it be a bug?

Cheers,
Wincent

Created Lighthouse ticket to track the regression:

http://rails.lighthouseapp.com/projects/8994/tickets/2039