Port the Merb parts to Rails
As part of the merge of Merb and Rails, it is very natural that parts will be ported also. It is very needed in some applications (including mine). Makes the app much more modular. I use now cells as a compromise (I use it for my widgets architecture), but it must be in rails core.
I believe he's refering to the feature "Merb Parts" described here: http://www.merbivore.com/features.html#parts
It's closest Rails equivalent would be the dead "Rails Components" last seen in Rails 1.2
With the excellent refactorings, this should be a cinch. I'd really like this to be a core part of the framework though, that way reusable apps can easily share reusable widgets powered by additional pages in the backend.
In my opinion creating reusable widgets of functionality (comprised of controller+views) is pretty fundamental. Should be a core piece of the framework.
How I ported rubyjunction.us from Merb to Rails: