Navigation of the project list is a problem for us too. It is simply difficult for end users to find what they are looking for in a long list of projects.
I thought it was interesting that that when you introduced a mere 14 starter projects you felt the need to group them under 4 categories to aid navigation ;-)
It would be great if you could consider introducing some customisable grouping or hierarchy for the main project list.
A note on 'tags'...
I'd imagine 'tags' were seen as the solution to finding/grouping projects. However, there are a couple of reasons why I think tags aren't as affective as they could be:
1) Users don't get exposed to tags as a navigational aid unless they enter "manage projects", where tags are available as filters. However, I'd imagine most users navigate to projects from the list on the workspace homepage/landing page (so never see these filter options).
2) The tag filters within 'manage projects' ironically suffer with the same issue that the project list suffers with i.e. we have a long list of tag filters that are difficult navigate/use and could benefit from some grouping!
If would be great if we could group the tag filters, perhaps in a similar way that filters are typically grouped on a retail site:
