Great analysis, this truly helped my understanding. In this way, my principals can CALL the monthly meetings PLC meetings (or communities of practice), but they may just be team meetings with a goal, meeting only because we are contracted to do so. From personal experience, a group that chooses to meet is always more productive and engaged.

The ten tips to establishing a PLN seem to be what we've been doing in 543 so far...

Great read. I especially like the part about "active participation" in a community. This seems a powerful learning theory - my students are always worried about their identity within their community, its no surprise that learning would work well here.