Following the steps in Visual Studio 2008 SP1, I installed both SDKs and created the flashing LED project and upon debugging through USB, found that the LED was not operational when pressing down the user button. The code was taken directly from the getting started page.

Are there any known reasons for this simple I/O program to not work? Would appreciate any insight. Thanks.

Share a very similar experience with the June post here:
http://devicesolutions.net/Support/...fault.aspx

However, even after running the 3.0 firmware patch, the dev board is unresponsive. Also, the code cannot be stepped through or debugged in Visual Studio. Breakpoints within the main are never even reached while debugging.

Can you try upgrading to 4.0 for everything (firmware, MS SDK and Device Solutions SDK).
Being unable to step through code is usually caused by a version mis-match.

Installed Microsoft .Net Framework 4.0 SDK and updated MeridianP firmware to 4.0 but now...
in the .Net Micro framework tab of the new Visual Studio solution Properties, the following error is displayed, "An error occurred trying to load the page.
afbac3d0-7526-4d80-9f42-2a975120bb5f". The .Net Micro Framework text is blank in the properties tab and upon clicking out and reclicking on the blank tab, the new error "An error occurred trying to load the page.
Unable to create the designer. File is already opened in an incompatible editor."

This is after updating both the .net SDK, upgrading the firmware to 4.0, and starting a completely new project within Visual Studio.

I haven't seen that before! My only suggestion would be to un-install everything (possibly including VS2008) and re-install.

FWIW I've also got the same issue on the computer I'm sitting at...
The machine had VStudio2k10 installed already. Did a fresh install of VStudio2k8, and some MF stuff, and I have the same error with the same guid afbac3d0-7526-4d80-9f42-2a975120bb5f

And I now have it working. I did a repair of all .NET MicroFramework msi files I could find and that seemed to fix everything