I can see several places in magnolia where you may need to configure a different behavior depending on "something" which usually is the request uri or host.

For example in MAGNOLIA-2308 you may need a different login form according to the url, or you may need a different default page for request done to different virtual hosts.
Instead of creating several new beans, which hold a pattern and a delegate object (for example: if url matches ./magnolia* use the standard login form, if url matches /mysite/* redirect to a magnolia page, and so on), we could create a standard bean that can be reused in any similar configuration