Mark Groves, one the of PMs on the Visual Studio Team System for Software Architects (VSTESA) team I've been working with to identify integration points (both long term and short term) between VSTESA and our Threat Analysis & Modeling tool, has a brief post up on his blog around SDM and Validators. Take a look here.

If you want to learn more about VSTESA extensibility, check out this post.

-Talhah