Yep. More the Unity Asset Store than workshop, but then I don't know workshop all that well. Here is why.
1. The community consists of divergent opinion on 3rd Party Plugins. We have those who will never touch non official plugins. And we have devs who throw any and every 3rd party plugin in. In fact in some cases it's so bad that dev's are throwing in broken plugins and obsolete plugins. Where as those who never use plugins are losing out on quality dev and time.
An official asset store fixes both. It offers a ranked repository. Increases plugin quality(because low quality will get filtered out). And people who make good plugins could optional charge a cost. This will will have numerous effects as noted in 2.
2. An asset store would improve every ones development time an quality. Offer financial aid to more advanced programmers. With the overall increase in quality this would get other developers to see C2 as more viable and mainstream. For example people could give/sell solid mobile templates for various games. Unique game controls. Right now there are some super clever code and stuff floating around in old forums posts. But unless you have been around for a few years people don't know about.
So having an asset store. Improves everyones quality. Improves perception. Increases money flow to programmers with talent. Having an asset store would stop with these ideas that C2 is for prototyping or toy games.