Rod Boothby at the innovation Creators blog has back to back awesome posts that help me answer questions about Learning2.0 in my corporate environment.
When to Use a Blog and When to use a wiki
This one is short and to the point. Very good stuff.
Email is critical to Enterprise2.0 and Office2.0
Well I wouldn't say critical but it will be useful for many years to come but reduced significantly with each passing year. I still hear the younger generations say things like, "I only use email to communicate with old people".