The Windows SDK for Windows 7 and .NET Framework 3.5 SP1 provides the documentation, samples, header files, libraries, and tools (including C++ compilers) that you need to develop applications to run on Windows 7 and the .NET Framework 3.5 SP1. To build and run .NET Framework applications, you must have the corresponding version of the .NET Framework installed. This SDK is compatible with Visual Studio® 2008, including Visual Studio Express Editions, which are available free of charge.

Please see the Release Notes for the full list of supported platforms, compilers, and Visual Studio versions and any late breaking issues. For detailed information about the content in this SDK, including a description of new content, please see the Getting Started section in the documentation.

Download at Microsoft Download

Build applications on a solid foundation; enable richer application experiences; and integrate the best of Windows and web services. The features and technologies of the Windows 7 operating system enable you to build the next generation of software applications.

More Info and Download : http://code.msdn.microsoft.com/Win7DeveloperGuide

As far as the security features, they discuss this on one of their dev pages.

some of the security changes require action on your part.  Adobe says..... "Some of these changes may require existing content to be updated to comply with stricter security rules. Other changes introduce new abilities that were previously unavailable or restricted by security rules."

You can get the download for version 10.0.12.36 here.

Last week I received an invitation to participate in the (free) preview of the new Microsoft PC Advisor program. We’re “not allowed” to share the initial survey and download link. The invitation to try out the PC Advisor made some intriguing promises—the app will monitor our PC for problems and give solutions in real time and it will monitor system settings for potential pitfalls. The survey that preceded our download was even more interesting, it hinted that Microsoft's ultimate goal for the new app is complete Apple domination.

On to the software. The invitation email we received said that the Microsoft PC Advisor will:

• Monitor your PC for problems and give you solutions in real-time to fix them.
• Keep your PC running smoothly with important software and driver updates
• Optimize your Windows experience with useful tips and tutorials
• Optimize your PC by monitoring and updating settings