All capability detection should be based on opengl extensions. In most cases when there's no opengl extension which can provide the functionality we can't support it. Recently I have improved our capability reporting quite a bit. Some of the caps from the page you pointed to are now reported but also a big number of them isn't reported because wined3d doesn't support those yet. Reporting caps which we don't handle is very bad, it would break games.
Roderick
Can we tie the gpu detection in to supporting fake/real alpha blending?