In November last year I presented, to a small group of my colleagues one evening, a summary of the new features in PowerShell v3 and why developers should care about PowerShell given that most PowerShell marketing targets the IT Pro types with their AD and Exchange management needs. I also spoke briefly about integrating PowerShell and C#.
The screencast of this presentation (~24 minutes) is available on the Readify in the Community website.
In February just past I presented a more detailed (with demos and code) and much more polished version of this presentation to the Sydney .NET User Group. Thanks to an excellent video recording and post-production setup at this user group, the full video of my presentation (~1 hour) is available to watch online on the SSW TV website.
Also, in the theme of PowerShell for Developers, Microsoft has just released the PowerShell 3 SDK Sample Pack containing many C# examples for extending PowerShell in numerous ways.