Where is the Team Foundation Beta 3 Extensibility Kit?

This question comes up fairly often (understandably), so I wanted to point out the update from Brian Harry in the forums:

https://forums.microsoft.com/msdn/ShowPost.aspx?PostID=120657

We were supposed to get it last week but there was a miscommunication between us and the VSIP team on when the VSIP SDK would be made available. We are working on finding an alternate mechanism to get our components available ASAP.