I think the title "Homepage" is problematical. An editor's "home" page is that editor's user page, which he/she can customize.
Something like "Engagement" or "Involvement" or "Editing" would be much better, I think.
One thing that wasn't clear from the project page is whether an editor can modify this page. I'd suggest that modifications be limited to actions that are pre-specified - delete, highlight, remove highlighting, move up or down in a list, or whatever. (One good option would be "Move to user page".)
- SuggestBot, on the English Wikipedia, if it's still around, is an interesting model.
- I'd vote for this as a tab for newcomers that is optional for experienced editors (and can be removed as a tab by going into Preferences)
- You absolutely want to post something on the User Talk page that this page has been created for the newcomer, as well as providing a link in a welcoming email.
- Designing this for experienced editors is scope creep, but a panel showing the "impact" of one's editing is great for any level of editor. Panels that could be added to the page, later, for experienced editors, might include things like information from projects that the editor has joined, edit counts (history summary), and tracking of modules completed within an editing self-study program.