I'll admit, I was originally in the OpenGL camp. OpenGL + GLUT was just vastly easier than DirectX for those of us with no Windows programming experience (even with the "easy to use" application framework they introduced in DirectX 8 or 9). Plus, I was fortunate to use it in a graphics programming class I had as an undergrad.
However, as part of my renewed interest in game programming, the coming release of Vista and DirectX 10, and the apparent demise of OpenGL, I decided to give DirectX another shot. But that requires tools.
The DirectX SDK is easy enough. That's been freely available for some time. A compiler and other development tools... that's a different story. I'd known about Visual C++ Toolkit 2003 (now deprecated, free command-line tools) for sometime, but I didn't know that they'd gone another step further and introduced Visual C++ 2005 Express Edition. Basically the same thing, but now with an IDE to boot. Very sweet.
This actually got me to dust off my DirectX and WinAPI books and do a little Windows programming for the first time in quite a while.