Let's consider what is happening on this very forum- you are reaching out to a community to get an answer.

The quality of the response is truly on the quality of the network (participants) and the task focus.

Personally, I have use Facebook primarily for personal use, and LinkedIn for professional contact. Within LinkedIn, I have a much more qualified network, and an identified "trusted circle/board of directors" where I can fully understand and trust the feedback I am getting. I also know who to reach out to for specific questions, and why they would be contacted.

This is achievable on Facebook, certainly, but I think value is optimized by clearly defining reasons for, and managing the relationships. If you have a clear idea of what the person responding to you has as experience, background, and agenda, it frames up the feedback appropriately.

From a corporate (policy) standpoint, the issue is how to get the benefit of the connections without the risks.

I think that facebook could help members to find the best solutions in elearning according to the specific conditions of the person.

IMO...
In an academic setting, where students are pretty much always in the learning environment (if not in class, still doing homework, studying, etc in the area) things like IM, Twitter, Wiki's, and maybe Facebook can all bring a lot to education.

In a corporate setting, not so much. How many employees are actively working away from the office?
When at the office, do you really want folks tweeting unrestricted? Should they be able to browse Facebook freely?
Sounds like a recipe for distraction!

Some environments restrict sites where their employees can go online. Some state their policy and let employees manage themselves.
Either way, I think such Web 2.0 'tools' would be better used if they could be restricted to the corporate environment. However perhaps I'm wrong - this was a big push with IM a couple years ago. Not sure what came of that. We all have a standard IM client installed for chatting internally...but many employees use it for chatting with their friends/relatives too.

Corporate environments are tricky as everyone's culture is different. In a general sense, while to concept of many Web 2.0 technologies could be very helpful, in an unrestricted sense, I see more opportunity for inefficiencies than gained efficiencies...

In other words, I think more people would be watching celebrity tweets than internal SME tweets. I think more people would be browsing Facebook to reconnect with an old flame than to dig through company profiles.

Corporate Wikis are a fairly restricted, useful item. The problem there is, how much effort should employees be putting into adding/editing the corporate wiki as opposed to doing whatever their job requires? How is that time accounted and billed?
CM