What is the value of social bookmarking to IT Pros?

I recently recorded a podcast with TechNet's Social Platform team, discussing the social platform, and the new TN social bookmarking in particular.  Listen to the podcast, and then leave feedback here.

Some points to think about:

1. Build authority: I'd follow mark russinovich's bookmarks, wouldn't you?
2. Reciprocity: the more I mark, the more value I add to you, and verse-vicea <network effects>
3. Proactivity: If you and I share a topology, say exchange on windows, and I notice in your marks that you've had FOO problem, but I haven't...yet... I can go check out the solution and maybe avoid the problem in the first place
4. De-Silo-fication: the solution to my users's email problem may lie in the exchange silo on TN, or the OWA/Outlook silo, or in the ISA silo, or - maybe in all three. Once I find the content I need, I can tag all three with the same tag (let's say "EXCHANGE RANGERS") and then find them again much faster if I ever need to. More importantly, YOU can find them, and maybe you hadn't thought to look in the ISA silo.
5. Pathfinding: For example, the hot Hyper-V topic now has a filterable, living database of the most popular links related to Hyper-V, along with an RSS Feed for Hyper-V. When you find a great site on this or any other topic, you can use the bookmarklet to tag it with the topic name (e.g. "hyper-v" and/or "deployment"). As of the launch, 40% of the bookmarks are not on Microsoft domains.