The reasoning behind offering different hacks to phpwcms on another site would not be to split things up as much as a way for people to distribute their hacks for those who might be able to use them. In my case I am making a blog functionality which lets users have a consistant means of blogging instead of manually having to add each part of the blog and such. This makes an rss feed of the blog a little more specific for a blog. The reason I am explaining this is to say that someone else might want to use this functionality and so it would be good if they could. Also I am learning a ton about phpwcms (and plan to write about it
The other reason for a repository of hacks would be for businesses who create a functionality or custom solution. It would give them a place to share what they did so others might be able to use it. I say this b/c the company I work has been looking for a good cms framework to base other projects off of and phpwcms looks to be it. If someone else made module or something that we could use or vice versa it would help in a very practical way.
So... after way too much typing
Thanks for taking the time to discuss this kind of stuff and please feel free to request specific work to be done or a tutorial to be written.