Geometry shaders? Yeah, you'd need a recent (and high-end) video card for those. Pixel shaders (more likely)? They've been a part of OpenGL for almost ten years, since they were one of the core new features of OpenGL 2.0.
Honestly, the only people who are going to have problems are the ones who have barebones systems from the beginning of the Windows XP era. Even a DX9 video card like a Radeon 9X00 is likely to have some pixel shader support.