Found this on Alex' blog (he posted it in German last week): Microsoft UK has released a document (PDF) titled "The Developer Highway Code" (The drive for safer coding), which covers the following topics:
- Integrating Security into the Lifecycle
- Security Objectives
- Web Application Security Design Guidelines
- Threat Modelling
- Security Architecture and Design
- Security Code Review
- Security Deployment Review
The document covers v1 and v2 of the .NET Framework, and it does contain useful checklists. Be sure to grab it!