Having shown you Stringle, I thought it'd be interesting to think what else it would need to be a usable tool.
Here's my thoughts:
A good range of tools that users can select from. Tony's working on this, so you should have a range to select from and can simply drag them into your toolset and give them a label (thus avoiding all that del.icio.us and URL stuff).
Easy way of adding new tool - if you come across a tool then you want to be able to add it simply by clicking a button. If we were providing students with a university social bookmarking tool, then this could be done easily.
Toolset related to resource - I think this would be quite powerful. If you select a particular tool then it has some metadata associated with it which automatically loads in the appropriate tool(s). Thus if you're doing a timeline activity the only tool available is a timeline, if you're doing a collaborative activity then maybe a discussion board and IM tool are displayed.
Easy add - as with tools, you don't really want people to mess around with OPML managers, so you need a neat way of adding content in.
Icons - next to the links in the grazr widget it would be good if you can identify different types of resources, e.g. activities had an icon or were styled a particular way.
Authentication - you're going to need some way of allocating roles and resources to individuals, which means all the tedious but mission critical stuff around linking with student record systems, assigning roles, security, etc.
Tracking - this is essentially dumb integration. If you really want to do tracking you need to know what people are doing in each of the tools. This might be insoluble if you want to allow an open system.
Usability - it's no oil painting at the moment and definitely could benefit from some good interface design.
Of course, you may be asking yourself 'why bother? Why not just use Pageflakes?' (or something similar). There may be something in this, but what impresses me is the way a system can be configured quite easily. More on this in the next post.