David, I agree with solution #1, until academics are comfortable using a range of online tools were are not going to see them widely used in learning activities.
Solution #2 is happening, perhaps not fast enough, but there is certainly more money allocated to teaching projects and teaching awards than a decade ago.
My #3 would be to get students using the tools to achieve particular learning goals - show them the range available and give them projects that are facilitated by particular tools. A group annotated bibliography using Delicious, Collaborate on a review of a film using Notemesh, Use Mindomo to plan your group project ad assign tasks ... etc. None of these are inconsistent with using a CMS to manage the course. The problem with many uses of Web 2.0 apps at the moment is the "Creepy Treehouse Effect"
With respect to your #3. This has some connection with a project I've been involved with and which also connects with my #3.
The project seeks to enable students to use their own blogs (e.g. on wordpress.com) as reflective journals. Which I think is a good match between task/goal (reflection etc) and tool (blog).
The loosely coupled aspect enters the picture through the tool we've developed called BAM/BIM.
BIM/BAM essentially provides the administration/management interface teaching staff need to manage and mark student use of the blogs and connect with institutional results processing systems.